The Third Fleet comprised 11 ships that set sail from the Kingdom of Great Britain in February, March and April 1791, bound for the Sydney penal settlement, with more than 2,000 convicts aboard. The passengers comprised convicts, military personnel and notable people sent to fill high positions in the colony. More important for the fledgling colony was that the ships also carried provisions.
The first ship to arrive in Sydney was the Mary Ann with its cargo of female convicts and provisions on 9 July 1791. Mary Ann had sailed on her own to Sydney Cove, and there is some argument about whether she was the last ship of the Second Fleet, or the first ship of the Third Fleet, or simply sailing independently, as was HMS Gorgon. The vessels that unambiguously belong to the third fleet all left together.
The ships that make up each fleet, however, are decided from the viewpoint of the settlers in Sydney Cove. For them, the second set of ships arrived in 1790 (June), and the third set of ships arrived in 1791 (July–October). The Mary Ann was a 1791 arrival.
The next ship to arrive just over three weeks later, on 1 August 1791, was Matilda. With Matilda came news that there were another nine ships making their way for Sydney, and which were expected to arrive shortly. The final vessel, Admiral Barrington, did not arrive until 16 October, nearly 11 weeks after Matilda, and 14 weeks after Mary Ann.