Proinsias Cassidy was born in 1900 in Balbriggan, Ireland, to a Catholic father and a Protestant mother. When he was sixteen, he joined the Irish Republican Brotherhood, along with his brother Billy. Together they took part in the Easter Rising of 1916.
Billy realized that the rebellion was doomed to failure and dragged young Proinsias away from the conflict, deserting. They began to walk home, stopping near a swamp to rest for the night.
During the night, Proinsias was attacked and bitten by a female vampire that inhabited the swamp. Billy shot it in the head and it, and Proinsias, fell into the swamp. Billy then ran away, assuming his brother was dead.
Cassidy awoke the next morning, still underwater. Upon exiting the swamp, he burst into flames. After doing this "three or four times" he decided to remain underwater until sunset. He finally emerged that night, voraciously hungry. Growing more and more desperate, he attempted to feed on a sheep but was caught and shot directly in the chest with a shotgun. Surviving this seemingly mortal wound, along with his reaction to sunlight and sudden increase in strength and speed, made Cassidy begin to realize that he was no longer human.
Cassidy was created by Garth Ennis and Steve Dillon.
Proinsias, having slowly realized that he wasn't human, thought it best that he stay "dead" rather than reveal to his brother and family what had happened. He hopped a boat, along with thousands of other immigrants, and came to America.
When he got to New York, he was enthralled. Tall buildings, bright lights, and more people than he'd ever seen in one place before. It was a brave new world, and he was determined to make the most of it.
He was swindled almost the moment he got off the boat. Another Irish immigrant approached him, promising to show him all the opportunities that America had to offer, and ran off with Proinsias' bags as soon as his back was turned.
Without money or a plan, he went to the first bar he saw that had an Irish-looking name. He got a drink for free from the bartender, who had a kind thought for the recently ripped-off, and looked around to see what to do next. In the back was an arm-wrestling contest. He figured that with his strength, he could win without too much trouble. Proinsias bet the champion twelve dollars that he could win, putting nothing more than his word up against it.
Proinsias won easily. The other man introduced himself as Mick MacCann and inquired as to the name of the man who had so handily beaten him. This was a good chance, Proinsias thought, to shed a bad name along with a bad past.
Cassidy in New York
Cassidy became a regular with MacCann over at McSorleys Old Ale House, an Irish bar that was a second home to many expatriates. There, they talked about the old home, and its troubles. They swapped stories about their conquests in the bed and in the battlefield, and mostly just drank and enjoyed each other's company.
While McSorley's was a certified boys' club, there were plenty of chances for Cassidy to meet women. His good looks and his reckless attitude caught the eye of many a young lady, and he had a great talent for gaining other peoples' confidence. With a slap on the back and a "How're yez!" he was your best friend.
Unfortunately, Cassidy's best friends tended to end up suffering.
His unnatural ability to heal himself, to resist aging and to stay vital long after most humans would die was a challenge to Cassidy. He had grown into something of a thrill-seeker, but because he was something more than human, his thrills had to be that much higher. It's no surprise, then, that he turned to drugs.
His drug use was light at first, just a little something to make him feel good. And none of his friends really noticed, either. They were such a varied group of characters that nobody gave much thought the the pale young man who always wore sunglasses. Nobody except MacCann.
From the moment Cassidy beat him in arm wrestling, MacCann knew there was something unusual about the young man. He watched, and considered, and then one day gave Cassidy a present - a copy of Bram Stoker's Dracula.
All the pieces fell into place then. A lot of it was nonsense, but enough of it was true to lead Cassidy to the conclusion that not only was he special, he was functionally immortal. At that point he looked around and realized that he'd known his friends at McSorley's for about twenty years. He wasn't getting older, but they were. He knew that he didn't want to see his friends get old.
So from then on, he stayed away from McSorley's and MacCann. But he kept up a lot of his old ways. Some things are hard to give up. Drugs, for example, and women. He convinced young women to support his drug habit, eventually turning them into junkies as well. Being human, however, they couldn't handle the pace that Cassidy set. Each relationship ended in tragedy.
Cassidy punched Gilly so hard he broke her jaw. When she went packing, he seduced her friend Joanie. They, too, found themselves living in filth and withdrawal. She escaped from him after he tried to suck her blood in lieu of a hit of heroin.
After that, Cassidy's life went into something of a decline. He became skeletally thin, living off the blood of rats. At one point, he was actually believed to be dead - he woke up underground, full of embalming fluid, and had to pick the stitches out of his eyes. Despite all this, however, he never seemed motivated enough to change his lifestyle. He got stronger, got some money, and started it all again. He fathered children on several women, but didn't keep track of any of them.
He returned to the New York party scene, and knew such luminaries as Dylan Thomas and Brendan Behan. He even met MacCann again, who seemed entirely unsurprised to see him after so many years.
That was when his longevity really hit. MacCann, the arm-wrestling champion, was old, bald and needed a cane. Cassidy still looked twenty-five, and he was likely to go on doing so forever. So he decided to hit the road.
Travels in America
Cassidy found America to be his playground. He traveled its length and breadth, bringing chaos in his wake. He stole money, seduced wives, and led the law on a merry chase. And loved every minute of it.
In New Orleans, however, he finally found something new. Another vampire.
His name was Eccarius, and he was disappointing from the start. Where Cassidy hadn't known much about vampires until long after he became one, Eccarius was no doubt a longtime fan of Anne Rice before he was Turned. He embraced his new role as a Childe of the Dark. He wore frilled shirts and capes, lived in a Gothic mansion and drank blood from crystal goblets. He spoke at length about their "dark curse" and "exquisite torment." He slept in a coffin.
He was, as Cassidy put it, a wanker.
In addition to his own affectations, Eccarius encouraged them in others. There was a group of disaffected youths in New Orleans who idolized Eccarius, who wanted to become like him. They called themselves, unsurprisingly, Les Enfents du Sang.
Les Enfents were the worst kind of vampire-worshippers. They met in a basement with arcane symbols painted in deep red on the walls. They wore black clothes and too much eye makeup. They wrote bad free-verse poetry about Eccarius. They even cut themselves and drank each other's blood. What was worse, Eccarius encouraged that kind of idol-worship.
Cassidy dragged Eccarius out by his ear, but not before breaking the jaw of Mako, the toughest of the group. From there, Cassidy set about Eccarius' re-education.
They spent several days around New Orleans, where Cassidy taught Eccarius that beer was better than blood, that they had nothing to fear from churches, and that nearly everything Eccarius thought he knew about being a vampire was wrong. In the end, they went back to Les Enfents' lair and mooned them. Because it would be funny.
In the end, Eccarius' ego won out over his reason. Cassidy found him draining the blood of one of the younger members of Les Enfents du Sang on the altar of a church. He loved the idea of being a vampire more than the reality of it. Cassidy knocked him unconscious and then nailed him to the roof of the church, where Eccarius exploded in the morning sun.
This was an important lesson for Cassidy, one that he learned, but never really absorbed: people don't like to change. Perhaps if he had understood that about not only other people but about himself, a lot of what happened in the subsequent years would have been different.
Unfortunately, he soon fell into the same patterns he'd had for nearly a century. While in New Orleans, he met a girl named Dee. They started going out together, but broke up when he hit her so hard that her eyeball burst.
After that, he went on the road again, planning on travelling to Dallas to open a bar he would call "The Grassy Knoll".
Cassidy, Tulip and Jesse
In Dallas, Cassidy was nearly carjacked by an angry blond woman with a gun. He refused to get out of the car, but was amused enough to give her a lift from the men who were trying to kill her. The woman introduced herself as Tulip, and while she wasn't sure where she was going, he was willing to drive with her for a while, so long as she drove during the daytime. On their way through Texas, they came to the town of Annville Texas and a destroyed church. Laying in the wreckage, completely unharmed, was Jesse Custer, Tulip's ex-boyfriend. Jesse possessed a special power - a Voice of Command that he received from the entity called Genesis.
Custer asked Cassidy to drive them away from the scene, which they did, but they were unable to outrun the Saint Of Killers. Only by the intervention of the local sheriff's department were they able to get away.
It wasn't long before Jesse figured out what Cassidy was, and was repelled by what he saw. He used his Voice to make Cassidy stop drinking a young man's blood, and called him a monster. Cassidy drove off in outrage, vowing never to see either of them again. He broke that vow, however, when he learned that the Saint of Killers was on his way to finding Jesse and Tulip.
Against his better judgment, Cassidy tried to rescue them. It failed, and the Saint was stopped by other means, but the attempt at rescue was the key factor in solidifying Jesse and Cassidy's friendship. Cassidy joined Jesse in his quest to find God and make him answer for abandoning His creation.
They went to New York to try and figure out where God might have gone to. He introduced them to an old friend of his, a freelance journalist named Si Coltrane, who thought he might be able to help. Unfortunately, Si turned out to be a vicious serial killer who very nearly got the three of them killed. It was another reminder for Cassidy that where he went, chaos followed. So he did the only thing he knew how. He ran.
While Jesse and Tulip went to Texas, Cassidy headed out to San Francisco to meet with an old girlfriend, Greta. She was into heroin, like so many of Cassidy's girlfriends, and had been living hard ever since he met her in 1966. Soon after he arrived in San Francisco she died of a heroin overdose.
When Jesse met up with him again, they discovered that Greta had been hired as a mule to move heroin by Bob Glover and Freddy Allen, Sexual Investigators. They went to Glover's office, where they found that the heroin was bound for an orgy at the estate of the wealthy and hedonistic Jesus DeSade. Together with Tulip, they went to the DeSade estate, looking to find the men who had given Greta the instrument of her death.
Unfortunately, there were people looking for Jesse Custer, and they were also at the DeSade estate. They were The Grail, led by a cold, calculating man named Starr. They attacked the party, killing multiple people in their search for Jesse Custer. When Starr was about to kill Tulip, Cassidy stepped in. He put on his best Texas accent (which wasn't actually very good) and pretended to be Jesse Custer.
The move saved Tulip's life, but it nearly killed him. Starr took Cassidy to Masada, the secret headquarters of The Grail in France. There, he discovered that not only was Cassidy lying about his identity, he was something other than human. From then on, Starr became increasingly interested in how much punishment Cassidy could take - from gunfire and grenades and the like - before he actually expired. He even brought in a professional sadist, Frankie Toscani, to shoot him to pieces with a rifle.
While in the Grail's hands, Cassidy was visited by God. He had been chased by Jesse for a long time, and He was giving him a chance to stop. He told Cassidy to pass the message on to Jesse - they had crossed paths twice, a third time would mean Jesse's death. Before He vanished, God named Cassidy "Beast," which was not entirely undeserved.
Cassidy was saved by Jesse Custer, who found out about Masada and made his way there solely to rescue his friend. Unlike Cassidy's earlier rescue attempt back in Texas, this one worked. They escaped Masada just before it was blown to pieces by high-powered explosives.
They returned to New York, where the three of them thought about their next move. Cassidy and Jesse stood atop the Empire State Building, and Cass promised Jesse that, no matter what, he would stick by him until his quest was through.
It was not long after that when Cassidy, perhaps with too much drink in him, confessed to Tulip that he loved her.
The next morning he apologized and swore it was just a reaction of the recent stress and the alcohol, and perhaps she forgave him. But she warned him that if he pushed the issue, she'd tell Jesse. And they both knew how Jesse would react.
As for their next step, Jesse intended to go to Arizona, to use the rituals of the Native Americans to try and contact Genesis. Cassidy had another idea - try New Orleans.
The Unraveling Begins
Cassidy had a friend in New Orleans, Xavier. Xavier was a voodoo priest, and thought he might be able to help Jesse out. Cassidy thought it might be a good chance to have some fun, catch up with old acquaintances and maybe have another chance with Tulip.
Typical of Cassidy, he had completely disregarded the conditions under which he left New Orleans. So, when Les Enfents du Sang nearly killed Tulip and Jesse and, in fact, succeeded in cutting off Cassidy's head, he was unjustly surprised. The attack by Les Enfents also resulted in the death of Xavier's girlfriend, Janis, which led him to warn Tulip.
He said that Cassidy wasn't necessarily evil. Just very, very short-sighted and selfish, with an amazing ability to get close to someone and then stab them in the back. It had happened to him, when Cassidy seduced the woman he loved, and he worried that it would happen to Jesse. Tulip, for her part, was perfectly able to understand what Xavier was saying, as Cassidy had been continuing to try to get between Jesse and herself. She promised herself that she would tell Jesse if Cassidy did just one more thing.
She didn't get the chance until it was much, much too late.
Jesse's plan to take peyote and talk to Genesis was interrupted by a full-scale war between the Saint of Killers and The Grail. It ended in nuclear holocaust.
They commandeered a military plane, and very nearly escaped from the devastation. Jesse, however, fell out of the unlocked door. Cassidy tried to haul him back in, but was burning under the desert sunlight. Jesse said to tell Tulip that he loved her, and then Commanded Cassidy to let him go.
After they reached safety, Cassidy and Tulip went on the run. Tulip was nearly destroyed by the loss of her lover, and turned to alcohol and pills to try to dull the pain, which Cassidy gladly procured for her. To his credit, he tried for a long time not to take advantage of her pain and loneliness. He just didn't try long enough. Eventually, he seduced her. While he didn't force her to stay drunk and stoned, he made sure that her narcotics were always available, and kept her moving and off the phones with the specter of Starr.
They traveled around the Southwest and California, hooking up with friends of Cassidy's - drug pushers and porn stars, mostly. Tulip was content in her haze for a long while until she finally woke up one day and decided she'd had enough. She shot Cassidy into the sunlight when he tried to stop her, and then drove off.
Cassidy found her in New York, and he also found Jesse - alive and very, very angry.
Jesse had learned all the dark secrets of Cassidy's history - the abuse, the drugs, and most unforgivably, the hitting of women - and was determined to see him pay for it. In Jesse's eyes, Cass was "an animal thinks it's a man." He told Cassidy to meet him in two months' time, in a bar called Hondo's in San Antonio. There, they would talk.
No matter what he might have hoped for, Cassidy knew that there was no way all this was going to end well. He knew that there would be a fight, and he wasn't sure how it would all end up. So he came up with a plan, and he made a deal.
When Custer showed up, two months later, Cassidy took one last shot at reconciliation with him. They sat in a bar and talked, and Cassidy tried to explain himself, but Jesse would have none of it. He told Cassidy that they were going to settle this with their fists, and he Commanded him to "fight like hell," knowing full well that Cassidy was easily ten times as strong as he was.
When the time came, a little before dawn, Cassidy went to the Alamo to meet Jesse. The fight started immediately, and right away, things were not going to plan. He had hoped that he'd be able to just beat Jesse up a lot, so that God could come in, remove Genesis from Jesse, and solve all of their problems. Unfortunately, Jesse had learned how to fight from the best, and knew that the best way to avoid being killed by Cassidy was to keep him off-guard.
He broke Cassidy's nose and filled his eyes with blood, and did a very good job of beating the hell out of him. As the fight drew to a close, Cassidy begged Jesse to give him another chance, to reach out a hand to a friend. He admitted his sins and understood their consequences, but needed someone, a friend, to forgive him if he was going to make a better life for himself. He reached out to Jesse Custer, hoping that he would take his hand.
Custer did, and Cassidy punched him in the chest, sending him flying.
That effectively ended the fight, but Cassidy at least knew where he stood. He knew he was damned, that his sins could never be forgiven. But he knew that as long as someone like Jesse was willing to reach out to him, there might be some good in his soul after all. He turned to the morning sun and exploded at daybreak.
A Second Chance
A moment later, Jesse was shot through the head by The Grail, and, as per Cassidy's arrangement with God, if not quite the way he'd intended, Genesis was free. All God had to do was hold up His end of the bargain which, to His credit, He did.
Jesse Custer was resurrected and made whole, but without the Voice. Cassidy was also brought back, without his curse. He was human again, able to watch the sunset, to grow old and to lead a new life. He would never see Jesse and Tulip again, but he knew that, finally, he had his second chance. And he was determined to, as his old friend Mick MacCann had said, "make the most of it."
The Grassy Knoll
Returning to his original plan of opening an Irish pub called "The Grassy Knoll", Cassidy commits to sobriety as a human despite working as a bartender, eventually becoming a sponsor for another former alcoholic: Billy Butcher, and returning to going by his first name: Proinsias. Gaining weight and growing a ponytail over time, Proinsias kicks out a group of drunken Americans dressed as stereotypical Irishmen so that Butcher can drink a club soda in peace, despite it being St. Patrick's Day (otherwise his most profitable day), before talking with him about their respective alcoholic pasts and what they miss. After Butcher's protége Wee Hughie arrives to meet with him, Proinsias pours him a Guinness, before leaving him and Butcher to discuss their plans for the G-Men, Vought-American, and the Seven, and closing up the bar after the duo leave, smiling.