Jack Sparrow is the eccentric, but cunning captain of the Black Pearl.
In his early years, he was captian of a ship called the Barnacle until he was forced to years of service to the East India Trading Company. After he had worked for the company for several years, he was given a new ship: the Wicked Wench. He went on a quest to find Kerma, an island containing legendary treasure. Once he found it, he decided to betray his master, Cutler Becket and hide the treasure for himself. However, Becket found him and marked him as a pirate, while his soldiers burned the Wicked Wench. He made a bargain with the captain of the Flying Dutchman, DavyJones, to resurrect his beloved ship. Afterwards, it was renamed the Black Pearl.
The Dead Man's Chest
"Any idea when Jones might release said terrible beastie?"
"I already told you, Jack. Your time is up. It comes now, drawn with ravenous hunger to the man what bears...the Black Spot."
―Jack Sparrow and Bootstrap Bill Turner[src]
A year after his great escape from Port Royal, Jack realized his freedom came at a cost. The debt he had sworn to Davy Jones thirteen years prior had still not been paid. Whether Jack had the foresight to attempt to call off the debt, or whether it was simply a coincidence is unknown, but Jack embarked on a quest to locate the Dead Man's Chest, which legends say contained the still-beating heart of Davy Jones. But first, Jack allowed himself to be captured by the corsairs off the Canary Islands and taken to the Turkish prison in order to obtain information he needs to solve his impending dilemma.
He soon happened upon a valuable drawing of a key in a Turkish prison, giving him an advantage in his quest by figuring out that he must find the key itself. Jack was able to obtain this drawing, but soon encountered trouble, and fled the island within the confines of a coffin launched out to sea. In the middle of the Mediterranean Sea, Jack used the coffin as a makeshift boat to return to the Black Pearl, where he informed his crew of his new venture. Confused, mostly because of Jack not telling exactly what to look for, the crew of the Black Pearl agreed to sail off to search for the key and what the key might unlock.
That night, Jack was visited in the Pearl's cellar by Bootstrap Bill Turner, currently serving as part of Davy
Jones' crew aboard the Flying Dutchman. Turner informed Jack that his time was up, and Jones was calling in his debt. To reinforce this, Turner branded Jack with the Black Spot, setting fear into Jack's heart and causing him to begin his quest for the key with all haste. He was so fearful of what his debt might entail, when he lost his hat, he told his crew to leave it. It was through this fear that Jack could not bring himself even to tell his crew what forces pursued them.