In early autumn 1916 the New Zealand Division was sent to join the Somme Offensive. They arrived on the 8th of September at their camp near Fricourt Wood, a few miles behind the front line and started preparing for their first big offensive, planned for the 15th. The Division's sector of the front, stretched from Longueval west to near the by-now infamous High Wood.
On the 12th the division moved up to the frontline by way of Caterpillar Valley and Carlton trench which ran along the ridge immediately behind what is now the Caterpillar Valley Cemetery. The following days were spent preparing and digging new trenches, one of them (Otago) being 100 yards forward of the front-line.
On the morning of the 15th at 6:20, following the creeping artillery barrage that had been laid down by the divisional guns, the 2nd Brigade's Auckland and Otago Battalions advanced on their first objective, the Switch trench line, and seized it within an hour.
The Division would be at the front for 22 consecutive days, longer than any other division. By the time they were withdrawn, on 4th October, they would have taken all their assigned objectives with great success but also at great cost. The Division would suffer more than 7000 casualties, of which 2000 were killed, their greatest loss of any single battle during WW1. 1205 soldiers have no known grave. They are commemorated on the New Zealand Memorial Wall at Caterpillar Valley Cemetery.
In 2004 one such soldier was exhumed and returned to New Zealand and is now buried in the Tomb of the Unknown Warrior at the National War Memorial in Wellington – a symbol of the more than 18,000 New Zealanders who lost their lives during WWI.