A third regiment associated with the county was the Surrey Yeomanry (Queen Mary’s Regiment), a territorial cavalry unit. It had its headquarters at Melbourne House, King’s Avenue, Clapham Park and its four squadrons (A to D) were based in Clapham Park, Guildford, West Croydon and Wimbledon.
At the outbreak of the war the Surrey Yeomanry was divided into those men who had agreed to serve overseas, who formed the 1/1st Surrey Yeomanry and those who had not so agreed, who formed the 2/1st Surrey Yeomanry. In 1915 a 3/1st Surrey Yeomanry was formed as a training, draft-supplying reserve.
A and B squadrons of the 1/1st Surrey Yeomanry served overseas on the Western Front and in Salonika and C Squadron took part in the Gallipoli campaign and then served on the Western Front until being converted into an infantry unit and absorbed into the 10th Battalion of the Queen’s Royal West Surreys. The 2/1st Surrey Yeomanry became a cyclist unit, serving in England and Ireland.