The First Surreys went into the line near the much fought-over Hill 60, now a quiet sector used by both sides to rest exhausted divisions. It was not until May 1917 that the battalion began training for a new attack at Messines. Assisted by a series of large mines (including one under Hill 60), the pre-dawn assault at Messines was highly successful. The First Surreys, in support for 142 Bde, moved forward and by 06.15 were in their jumping-off position in the newly captured trenches. A and C Companies advanced and took 'Oaf Line', the German support line, after which they were to seize the spoil bank thrown up from canal construction, then wheel right and cross the canal. B and D Companies jumped off towards the spoil bank at 07.30, but the unit to their left was held up in 'Battle Wood', from which enemy machine-guns enfiladed the battalion as it advanced. Only a foothold could be gained on the spoil bank, so the divisional commander withdrew the troops and ordered a fresh bombardment of the position from 14.00 to 19.00. Reinforced, the First Surreys were due to renew the assault when the Germans put down an intense barrage, rendering attack impossible. The following day the battalion had to fend off several German counter-attacks. At Messines – generally considered a successful battle – the battalion's casualties were seven officers and 237 other ranks killed and wounded.