Thomas Anstis began his pirate career in 1718, after leaving Providence harbor on board a sloop named Buck. Led by famed buccaneer Captain Howell Davis, the crew pillaged and burned or traded for a host of merchant ships and slavers for several months.
When Captain Davis was murdered in June 1719, Thomas Anstis gained a new boss: Bartholomew Roberts, also known as Black Bart. In 1721, Black Bart and his crew managed to overpower an 18-gun brigantine, which they promptly renamed the 'Good Fortune.' Roberts appointed Thomas Anstis as captain and they divided crews between the ships.
En route from the West Indies to Africa in April 1721, Captain Anstis purloined the Good Fortune along with its crew and slipped off to seek his own fortune in the Caribbean. Along the way, he was able to attack and seize goods from merchant ships. He also gained a reputation for brutality. In one reported instance, he and his crew viciously attacked a young woman before killing her and throwing the body overboard.
In the following months, Thomas Anstis continued plundering and seizing or burning ships. Upon capturing the much larger Morning Star, Anstis placed John Fenn in the position of captain, as he preferred steering his own, smaller ship.
The two men reportedly amassed a large crew, many of whom began to request leave of the ships and of the pirate life. Anstis and Fenn agreed to seek a pardon from the King of England. They sent a petition stating that Bartholomew Roberts had forced them into piratical ways. If honored, this plea would mean they could claim innocence if accosted at sea by authorities. While awaiting the King's verdict, they retreated to a secluded island off Cuba, where they feasted and celebrated for nine months.
Finally, they received word in August 1722 that the King had shown no interest in accepting their request. Captains Anstis and Fenn once again returned to sea and to a life of piracy.
Thomas Anstis experienced a downturn in his fortune after leaving the island. While in the Grand Caymans, a storm caused the Morning Star to wreck. Anstis attempted a rescue but came under attack by the Hector and the Adventure. Captain Anstis and his crew, along with Fenn, managed to escape. They hobbled in to the Bay of Honduras in hopes of refitting the brigantine.
By December of 1722, Captain Thomas Anstis had plundered and kept a second ship to which he appointed Fenn captain. They headed toward the Bahamas in search of further riches. Upon reaching Tobago, they came under attack by a man of war, the Winchelsea. Fenn made a run for the woods but was captured, while Anstis escaped. He then faced a mutiny by his men, however, and was killed. The crew surrendered at the Southern Caribbean island of Curacco.