Under the command of 50th Northumbrian, the 4/7 DG were involved in very heavy fighting in the capture of St Pierre La Vieille. The drive south to Conde sur Noireau or Operation Black-water followed. The continuous fighting in support, alternately, of two divisions had its effect; casualties had been heavy. The 5th Royal Inniskilling Dragoon Guards and the 86th (East Anglian) (Hertfordshire Yeomanry) Field Regiment, Royal Artillery who, like the Essex Yeomanry, had Sexton self-propelled 25 pounders, were placed under command.