The Enterprise D is a Galaxy Class Starship and was the flagship of the Federation the whole time it was in service. The Ship's main Captain in it's entire line of service was Captain Jean-Luc Picard. There were a few others that Captained the ship for brief periods of time when Picard was unavailable but he was never away from the ship for more than about a few weeks. The ship would be eventually destroyed when it crashes on a planet after a battle with Klingons.
The Enterprise D was created for the Star Trek: The Next Generation Television show. As the first Star Trek program this was also created by Gene Roddenberry.