In early 1942 the Japanese captured much of Papua New Guinea in the Southwest Pacific.

In early 1942 the Japanese captured much of Papua New Guinea in the Southwest Pacific. This action put Australia in substantial peril as it was now directly threatened by the ever-encroaching Japanese. 

A key position for Australia’s survival was the base at Port Moresby on the southern coast of Papua New Guinea. This base represented a last line of defence before Australia itself, and its retention was vitally important to the beleaguered commonwealth.

 This fact was not lost upon the Japanese, who launched a seaborne effort to capture the port in early May, but this resulted in the battle of the Coral Sea in which an American naval force rebuffed the Japanese invasion attempt. This action represented Japan’s first strategic setback of the war. 

One month later the Japanese suffered a far greater reversal when American naval forces scored a stunning victory over the Imperial Japanese Navy during the battle of Midway.

Yet, undeterred by these mishaps, the Japanese were still intent on capturing Port Moresby. Accordingly, on 21 July Japanese forces landed at Buna and Gona on Papua New Guinea’s northeast coast. From there, the Japanese pushed inland to capture Kokoda and its strategically important airfield on 29 July. They then continued southward on an overland trek along the jungle-clad Kokoda Track with the aim of capturing Port Moresby, but their offensive made slow progress against the inhospitable terrain and the stubborn Australian resistance. In particular, two battalions of the Australian 30th Brigade were able to hold up the Japanese advance in the area between Kokoda and Isurava for a month. Concurrently, the Australians moved reinforcements into the Kokoda area through Port Moresby, which eventually included two brigades (the 21st and 25th) of the veteran 7th Australian Division. During the course of these sea movements, the navy enjoyed a small victory on 29 August when the Australian destroyer *Arunta* sank the Japanese submarine *RO33* ten miles southeast of the endangered port.

While this was underway, on 25 August the Japanese launched a small seaborne assault against the newly established Australian airfield at Milne Bay on the far eastern tip of Papua New Guinea. This assault met strong opposition from two Australian infantry brigades, two Australian artillery units, an American engineer unit and two RAAF Kittyhawk fighter squadrons. For ten days the Australians successfully repulsed every Japanese attempt to capture the airfield. During the battle, they received excellent support from the two Kittyhawk squadrons and other RAAF units that operated against both ground and maritime targets. In one action of particular consequence, RAAF Kittyhawks destroyed seven barges off Goodenough Island that stranded 350 Japanese marines of the 5th Sasebo and prevented them from participating in the battle. These strikes, along with stubborn ground resistance, quickly degraded Japanese resolve to continue the battle, and on 4 September the Japanese cancelled the operation and began evacuating their forces. In doing so, they left behind 751 dead and missing and brought back 335 wounded. Australian casualties amounted to 123 dead and 198 wounded. Although a minor battle, Milne Bay represented the first Allied land victory scored against the Japanese during the war.

Meanwhile, on the Kokoda front the Australians, bolstered by their growing strength, finally halted the Japanese advance at Ioribaiwa and the Imita Ridge in mid-September. Although less than 20 miles from Port Moresby, the Japanese were now at the end of their logistical endurance. Even more important, with major fighting now underway on Guadalcanal in the Solomon Islands, the Japanese decided they could not support both operations and on 24 September began withdrawing forces from their forward positions on the Kokoda Track. On 28 September the 7th Australian Division went onto the offensive to pursue the retreating Japanese on the Kokoda front. Advancing with two brigades, the 16th and 25th, the Australians retraced the route used by the Japanese during their earlier offensive. This was no easy task as the Japanese conducted a measured, fighting retreat while the Australians had to deal with extremely harsh terrain and their own logistical constraints. Over the next six weeks the Australians maintained steady pressure and slowly pushed the Japanese back across the Owen Stanley Mountain Range. On 2 November Australian forces captured Kokoda village and eleven days later reached the Kumusi River after routing a Japanese rearguard in the vicinity of Oivi-Gorari. Up to this point, the Japanese had largely conducted an orderly retreat, but this substantially broke down during this latter action as the Japanese suffered an estimated 600 fatalities including their commander, Major-General Tomitarō Horii, who drowned while attempting to cross the river. Other Japanese losses during this engagement included the abandonment of large amounts of materiel including 15 artillery pieces.

The victory at Oivi-Gorari signalled an end to the Kokoda campaign, but the fighting in eastern Papua New Guinea was far from over. Australian and American forces would soon follow-up this triumph with a northern push to destroy the well-entrenched Japanese forces positioned in the Buna and Gona area. This would be a difficult fight lasting until late January 1943 (which I will cover in greater detail in a future post). Suffice it to say, the Australians and their American partners were successful in this undertaking thus gaining them control over all of eastern Papua New Guinea. In the process, they inflicted an estimated 12,000 fatalities upon the Japanese through the duration of the six-month campaign (including losses already discussed) with another 350 taken prisoner. Their own losses in attaining this victory amounted to 5,698 Australian and 2,848 American casualties of which 2,165 and 930 were killed respectively.

Pictured here are members of the Australian 39th Battalion on parade after weeks of hard fighting during the Kokoda campaign. Their bedraggled dress reflects the difficult conditions in which these men fought. Parer, Damien Peter, public domain. Also pictured is a RAAF Kittyhawk of No. 75 Squadron in Milne Bay in September 1942. Unknown author, public domain. Finally pictured is the aforementioned Australian destroyer *Arunta*, which destroyed the Japanese submarine *RO33* off Port Moresby. USN, public domain. For more information on this and other related topics, see ***Forgotten War, the British Empire and Commonwealth’s Epic Struggle Against Imperial Japan, 1941-1945***.