Northumberland was launched in 1780 to serve as a regular ship of the British East India Company (EIC).

EIC voyage #1 (1781–1784): Captain James Rees acquired a letter of marque on 21 April 1781.

When she finally left, Rees was unable to take the route he had originally intended and had to sail westward.

[1] After he had arrived in China, Rees wrote a letter in which he mentioned the loss of the men at New Guinea.

[1] EIC voyage #2 (1785–1787): On 2 April 1785 soldiers on board Northumberland at Spithead staged a mutiny.

[2] EIC voyage #3 (1788–1789): Captain Rees sailed from the Downs on 4 April 1788, bound for Bombay and Bengal.

Homeward bound, she was at Cox's Island on 19 February 1789, reached St Helena on 2 June, and arrived at the Downs on 2 August.

[1] EIC voyage #4 (1791–1792): On 22 March 1791 Lyon, Bartlet, master, was setting out for Cork and Newfoundland when she ran into Northumberland, carrying away her main and mizzen masts, and then grounded at Tilbury Fort.

[1] EIC voyage #5 (1793–1794): Captain Charles Jones received a letter of marque on 18 May 1793, following the outbreak of war with France.

She had sailed with a convoy of Indiamen that were bringing General Alured Clarke and his troops for the invasion of the Cape Colony.

However, Sphinx ran into Warren Hastings and both vessels returned to port, accompanied by Exeter.

[11] Northumberland and the convoy arrived at False Bay on 4 September, and the Cape of Good Hope on 1 October.