Built by the Tyneside shipbuilder Hawthorn Leslie, the destroyer was launched in 1915 and joined the Harwich Force as an anti-submarine escort for merchant ships in the Southwest Approaches and English Channel.

In 1918, the vessel supported attacks by British monitors and submarines against Zeebrugge and escorted Vindictive to Ostend where the retired protected cruiser was sunk as a blockship.

[1] Consequentially, they issued a set of requirements that were similar to those that had led to the previous year's L class, such as mounting four torpedo tubes, except for a higher speed of 36 knots (41 mph; 67 km/h).

[7] Mansfield had a main armament consisting of three single QF 4-inch (102 mm) Mk IV guns on the centreline, with one on the forecastle, one aft on a raised platform and one between the middle funnels.

[13] The warship was deployed to Milford Haven on anti-submarine duties to protect merchant ships sailing in the Southwest Approaches, arriving on 14 June.

[14] The vessel spent the following months escorting ships arriving and departing from Avonmouth and Devonport to cross the Atlantic to Canada and troopships leaving Liverpool for the Dardanelles.

[25] On 23 April 1918, the destroyer was part of the escort for the monitors HMS General Craufurd, Lord Clive, Marshal Soult and Prince Eugene for their attack on Zeebrugge.

[28] After the Armistice that ended the war, the Royal Navy returned to a peacetime level of strength and both the number of ships and personnel needed to be reduced to save money.

[30] However, the harsh conditions of wartime operations, particularly the combination of high speed and the poor weather that is typical of the North Sea, exacerbated by the fact that the hull was not galvanised, meant that the ship was soon worn out.