In 1913 he joined the Territorial Army as second lieutenant in the Yorkshire Hussars yeomanry. This included the raising of volunteer troops of cavalry consisting of gentlemen and yeomanry. The reforms reorganised the militia, yeomanry and volunteers into the new Territorial Force. Squadrons of the Royal Wessex Yeomanry. Lefort was subsequently seconded to the First Aid Nursing Yeomanry (FANY). This officially created the Imperial Yeomanry (IY). Horne was a Lieutenant in the Surrey Yeomanry. Orangism then spread into the Yeomanry and Militia. He served with the Queen's Own Mercian Yeomanry. The force was known collectively as the "Irish Yeomanry". This included the Berkshire (Hungerford) Imperial Yeomanry (Dragoons), renamed on 17 April 1901. This new force was called the "Imperial Yeomanry". Two squadrons and one troop of Berkshire Yeomanry (6th Mounted Brigade) defended the front. Dudley was commissioned into the Worcestershire Yeomanry in 1912. They were followed by the DD tanks of C Sqn, Staffordshire Yeomanry.