Portia initially served with the Grand Fleet but was allocated to convoy escort duties in early 1917.

296 long tons (301 t) of oil were carried, giving a design range of 3,450 nautical miles (6,390 km; 3,970 mi) at 15 kn (28 km/h; 17 mph).

[4] Portia was laid down by Scotts Shipbuilding and Engineering Company of Greenock with the yard number 475 in May 1915, launched on 10 August the following year and completed on 24 October.

[8] Portia was transferred from the Grand Fleet on 23 January 1917 and allocated to anti-submarine operations after the German navy declared unrestricted submarine warfare in February 1917.

[9] On 14 February, the destroyer joined sister ships Partridge, Plover and Rob Roy in hunting the submarine SM UC-44.

[12] After the Armistice of 11 November 1918 the Royal Navy returned to a peacetime level of mobilisation, and surplus vessels were placed in reserve.