The crew of the Federation Galaxy Class Starship Enterprise D (NCC-1701-D) existed seven years and was almost completely under the command of Captain Picard. The main officers of the Enterprise changed very little in that time before it was destroyed when it was attacked by a rouge Klingon cruiser.
The crew of the Enterprise was created by Gene Roddenberry for the Star Trek: The Next Generation television show. Roddenberry wanted a larger ship than the original Enterprise. It was double in size with a compliment of over a thousand, compared to the Original that had a compliment of four-hundred and thirty.
The team of the Enterprise changed very little in the seven years it existed. The crew started out with a core group of officers. Jean-Luc Picard Captain, William Riker First Officer, Data, Second Officer, Deanna Troi Councilor, Beverly Crusher Chief Medical Officer, Natasha Yar Secruity Cheif, Worf, Geordi LaForge and Miles O'Brien. O'Brien was most likely a Non-Commissioned Officer. There seemed to be a staff of chief engineers of a revolving door of Chief Engineers as the position changed as least three times during the first year of the Enterprise D's Mission. Wesley Crusher also made acting Ensign at this time.
After the first year of service Yar was killed in the line of duty and Beverly Crusher left the crew to work at Starfleet Medical. Kathrine Pulaski took over a Chief Medical Officer. Worf was promoted as Chief of Security and LaForge was promoted to Chief of Engineering. In the the third year of the Enterprise D's mission Reginald Barclay joined the crew. Barkley looked to have a short career on the Flagship of the Federation but soon proved to be a very valuble officer and stayed onboard until the ship was destroyed. One year la W. Crusher was promoted to full Ensign and went of to Starfleet Academy.
In the fifth year of the Enterprise D's mission Ensign Ro Laren was added to the crew despite her being court martialed previously. She stayed on in the sixth year of the mission but left for special training at about the same O'Brien left for his new position on the Deep Space Nine Space Station. In the last year on the mission Ro came back only to leave the Federation on her first mission.