Francis Castle Junior was the son of Frank Castle. He was Frank's ticket to a normal life after his life as a soldier during the Vietnam war. Things finally seemed to calm down for them as Frank once more learned to live life in peace-time. However, disaster struck when Francis, his sister Lisa and his parents went for a pick-nick in Central Park.
There they where witnesses to a mob execution. During this time, the mob fired on the family as well, fatally hitting Francis and the other family. Frank was also gunned down but survived. These events and the death of Francis, Maria and Lisa where the trigger for Frank Castle to become the Punisher.
Francis Castle Junior was created by Gerry Conway and Tony DeZuniga and first appeared in the black and white magazine known as Marvel Preview Issue #2 (1975), that depicts the origin of the Punisher for the first time.
Major Story Arcs
In Dark Reign, Frank Castle - The Punisher - was gunning after Norman Osborn. He decided to take down The Hood. This decision did not turn out well for Frank. Frank soon found that The Hood was working with Frank's old partner, Microchip, and that Microchip had allied himself with The Hood for two reasons; one, he owed The Hood for bringing him back, and two, The Hood promised to resurrect his dead son.
Eventually Frank's crusade came down to a final standoff. Microchip, Frank, The Hood, and the corpses of Frank's family and Microchip's son gathered. All Micro had to do to resurrect his son and Frank's family - according to The Hood's rules - was kill a SHIELD agent. Micro dutifully obliged, and Frank was horrified to watch as the caskets of his dead family opened once more.
Frank then grabbed a flamethrower from a recently resurrected d-list villain The Hood had sent after him, and burnt his family and Micro's son alive, knowing that they were meant to be dead.