The force began deploying in late 1941, and following Japan's entry into the war, it was drawn into the fighting in response to the Japanese invasion of Portuguese and Dutch Timor in February 1942.

Despite reinforcements from the 2/4th Independent Company arriving in September 1942, the Japanese offensive eventually resulted in the withdrawal of Allied troops over the period December 1942 to January 1943, with the commandos being withdrawn by sea.

In December 1941, due to concerns about a Japanese invasion, the Dutch requested that Australian forces be sent to both Koepang and Ambon under provisions that had been agreed to in a conference at Singapore earlier in the year.

Additional Australian support staff arrived at Kupang on 12 February, including Brigadier William Veale, who had been made the Allied commanding officer on Timor.

[4] The airfield at Penfui in Dutch Timor also became a key air link between Australia and American forces fighting in the Philippines under General Douglas MacArthur.

[5] Penfui came under attack from Japanese aircraft on 26 and 30 January 1942, but the raids were hampered by the British anti-aircraft gunners and, to a lesser degree, by P-40 fighters of the 33rd Pursuit Squadron, United States Army Air Forces, 11 of which were based in Darwin.

[12][13] Sparrow Force could not be reinforced further and as the Japanese moved to complete their envelopment of the Netherlands East Indies, Timor was seemingly the next logical target.

[16] Colin Doig provides different figures, though, stating that of the 14 men on the truck, 13 were shot, with one surviving (Keith Hayes) and one (Peter Alexander) being marched away to be a POW for the rest of the war.

The bombing was followed up by the landing of the main body of the 228th Regimental Group—two battalions totalling around 4,000 men—on the undefended southwest side of the island, at the Paha River.

[16] Leggatt ordered the destruction of the airfield, but the Allied line of retreat towards Champlong had been cut off by the dropping of about 500[19] Japanese marine paratroopers, from the 3rd Yokosuka Special Naval Landing Force, near Usua, 22 km (14 mi) east of Kupang.

[21] The 2/2nd Independent Company was specially trained for commando-style, stay behind operations and it had its own engineers and signalers, although it lacked heavy weapons and vehicles.

[23] Doi sent the Australian honorary consul, David Ross, also the local Qantas agent, to find the commandos and pass on a demand to surrender.

"[citation needed] Ross gave the commandos information on the disposition of Japanese forces and also provided a note in Portuguese, stating that anyone supplying them would be later reimbursed by the Australian government.

[26] On 24 May, Veale and Van Straten were evacuated from the south east coast by an RAAF Catalina and Spence was appointed commanding officer, after being promoted to lieutenant colonel.

Because of this requirement and the overall Allied strategy of recapturing areas to the east, in New Guinea and the Solomon Islands, Blamey recommended that the campaign in Timor should be sustained for as long as possible, but not expanded.

The Japanese commander drew a parallel with the efforts of Afrikaner commandos of the Second Boer War and said that he realised it would take a force 10 times that of the Allies to win.

[26] In August, the Japanese 48th Division—commanded by Lieutenant General Yuichi Tsuchihashi—began arriving from the Philippines and garrisoned Kupang, Dili and Malacca, relieving the Ito detachment.

The offensive ended on 19 August when the main Japanese force was withdrawn to Rabaul, but not before they secured the central town of Maubisse and the southern port of Beco.

[26] By October, the Japanese had succeeded in recruiting significant numbers of Timorese civilians, who suffered severe casualties when used in frontal assaults against the Allies.

On 1 November, the Allied high command approved the issuing of weapons to Portuguese officials, a policy which had previously been carried out on an informal basis.

[26] Also during November, the Australian Army's public relations branch arranged to send the Academy Award-winning documentary filmmaker Damien Parer, and a war correspondent named Bill Marien, to Timor.

[citation needed] By the end of 1942, the chances of the Allies re-taking Timor were remote, as there were now 12,000 Japanese troops on the island and the commandos were coming into increasing contact with the enemy.

Likewise, with the Australian Army fighting a number of costly battles against the Japanese beachheads around Buna in New Guinea, there were currently insufficient resources to continue operations in Timor.

[33] On 9, 15 and 18 December, the remainder of the original Sparrow Force—except for a few officers—was evacuated with Portuguese civilians to Darwin by the Dutch destroyer HNLMS Tjerk Hiddes, under the command of captain W. J.

At Singapore, the Sparrow Force men were marched 15 miles (24 km) to Changi Barracks where they were medically examined and assessed for employment in labour camps throughout South East Asia.

In Japan, those who had been transported on the Tofuku Maru were moved by train to Hiraoka where they were held at the Tokyo #2 Detached (Mitsushima) POW Camp.

[citation needed] Many died from disease or accidents in labour camps on the Siam-Burma Railway, in Sumatra, Japan, Java, Borneo, and Changi Prison.

"[citation needed] The 2/2nd Independent Company was renamed the 2/2 Commando Squadron and fought in New Guinea and New Britain, ending the war in Rabaul.

In contrast to those in Java, Ambon or Rabaul, Australian operations in Timor had been far more successful, even if it was also largely a token effort in the face of overwhelming Japanese strength.

Australian troops then supervised the disposal of arms by Japanese work parties before returning to West Timor for the surrender of the commander of the 48th Division, Lt. Gen. Yamada Kunitaro.