The campaign began in September 1943 following the 7th Division's drive on Lae, as part of the wider New Guinea campaign, which saw the 9th Division carrying out operations along the Huon Peninsula on the coast to the east, while the 7th moved towards the west. Carrying out a number of smaller-scale operations, the units of the 21st and 25th Brigades advanced up the Markham and Ramu Valleys. Apart from a significant engagement around Kaiapit, where the 2/6th Commando Squadron captured the village and killed over 200 Japanese, the Australians were barely resisted as they advanced and they arrived in Dumpu in early October. 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.