He was the captain of the ghost ship in the first film. Captain Barbossa. He left jack on an island and went after the cortez treasure which was cursed.
In POTC3 "At World's End", Will will team up with Barbossa to travel to the Worlds End (Asia) to rescue Jack, who has been captured by a vile chinese pirate played by Chow Yun Fat. The opening scene is set in a huge singapore harbour and is one of the largest indoor sets ever built.