[1] His family evidently had Loyalist sympathies as he was entrusted to the care of a maternal uncle, attached to the British forces in New York, after the death of his father in 1778 (he crossed the line under a flag of truce to join this relative).

[3] The first recorded mention of Winthrop as a midshipman is aboard admiral Rodney's flagship HMS Formidable during the Battle of the Saintes on 12 April 1782.

Winthrop superintended the landing of troops so successfully that he was rewarded with the honor of conveying Sir Home Popham's dispatch to London.

[8][9] In the Summer of 1799 Winthrop (still commanding HMS Circe) was put in charge of a squadron of frigates, comprising Jalouse, Pylades, Espiegle, and Tisiphone.

Due to sloppiness of the officers conducting the pilot boat in which they approached the Dutch fleet, the British parlimentaires were able to collect important information about the state of readiness and the morale of the crews.

They also appear to have conspired with several Dutch officers to influence admiral Story and to foment a mutiny among the crew of the flagship Washington, which later brought about the surrender of the squadron without firing a shot.