Battle of Dumpu

Battle of Dumpu
Part of the Markham, Ramu and Finisterre campaigns, World War II
Australian troops cross a bridge over the 19-kilometre-per-hour (10 kn) Gusap River on 25 October 1943
Date 22 September – 4 October 1943 Location Dumpu, Territory of New Guinea Result Allied victory
Belligerents
Australia  United States	Japan
Commanders and leaders
Ivan Dougherty	Masutaro Nakai
Units involved
21st Brigade	78th Infantry Regiment
Casualties and losses
5 dead 8 wounded 119 sick	unknown

The Battle of Dumpu was an action fought in September and October 1943 between Australian and Japanese forces in New Guinea during the Markham, Ramu and Finisterre campaigns of World War II. After the Battle of Kaiapit on 20 September 1943, in which the 2/6th Independent Company won a victory against a numerically superior Japanese force, Ivan Dougherty's 21st Infantry Brigade of the 7th Division advanced from Kaiapit to Dumpu in the Ramu Valley.

The 21st Infantry Brigade was opposed by Major General Masutaro Nakai's Nakai Detachment, which consisted of the 78th Infantry Regiment and one company of the 80th Infantry Regiment, both from the 20th Division. There was a series of minor actions, but the Australian advance was not delayed, and Dumpu was captured as planned.

During the entire advance, the Australian and American forces in the Ramu Valley were supplied by air. The capture of the Ramu Valley allowed a forward airbase to be developed at Gusap.