Camel, Snipe best ace, 1918. King, who was born on 13 May 1894 in Bathurst, New South Wales, joined the AIF as a trooper in the 12th Light Horse in July 1915. Posted to Egypt and served in Cairo and the Sinai Peninsula. King requested a transfer to the Royal Flying Corps (RFC) as a mechanic. He underwent training in England in January 1917, passing through the aeronautical school at Oxford en route to becoming a fully-fledged pilot. Finally attained his commission in October 1917, King joined 4 Squadron of the Australian Flying Corps the following March. He scored some 22 of his 26 victories in the final seven months of the war alone. Seven of these were achieved while flying the Sopwith Snipe, making him the highest scoring pilot to use the aircraft. DFC September 1918 and mentioned in despatches
No. 4 Squadron was operating its Sopwith Camels in hazardous, low-altitude support of Australian ground troops when King arrived in France, and he had little opportunity for air-to-air combat. The burly 6-foot-5-inch (196 cm) King—nicknamed "Bo", "Beau", or "Bow"—also had problems landing the Camel; crammed into its small cockpit, his large frame impeded control stick movement. The resulting rough landings annoyed his commanding officer, Major Wilfred McCloughry, brother of ace Edgar McCloughry. King's friend and fellow No. 4 Squadron pilot, Harry Cobby, recalled that "there was some speculation that he might go home—but he proved himself an impressive pilot". Cobby often took King on "special missions" to make mischief with the Germans; No. 4 Squadron found that two-man patrols were generally able to lure enemy aircraft into a fight, whereas larger formations tended to deter engagements. On 14 May 1918, King shot down a two-seat German scout that was spotting for artillery between Ypres and Bailleul, but clouds prevented him from confirming its destruction. By 20 May, he had been credited with his first aerial victory, over a Pfalz D.III near Kemmel–Neuve Église. He was promoted to lieutenant on 1 June. On 20 June, he destroyed a German balloon over Estaires; although vulnerable to attack with incendiary bullets, these large observation platforms were generally well protected by fighters and anti-aircraft defences, and were thus considered a dangerous but valuable target. Later that month he shot down two more aircraft, a Pfalz and a two-seat LVG, in the Lys region.
King registered his fifth victory, an LVG, after raiding Armentières on 25 July 1918. Four days later, he led a flight of six Camels from No. 4 Squadron escorting Airco DH.9 light bombers of the Royal Air Force in another raid on Armentières. In an action that the Australian official history highlighted as an "example of cool and skilful air fighting", the DH.9s completed their bombing mission while the Camels drove off an attacking force of at least ten German Fokkers, three of the Australians including King claiming victories, without any Allied losses. He destroyed a German two-seater on 3 August and another the following day, sharing the second with Herbert Watson. No. 4 Squadron was heavily engaged in the Allies' great offensive on the Western Front, launched with the Battle of Amiens on 8 August. King was credited with two victories—a balloon and an LVG—near Estaires during a bombing raid on 10 August. On 12 and 13 August, the Camels of No. 4 Squadron operated in a massed formation over Flanders with the S.E.5s of No. 2 Squadron AFC, the former's two flights led by Cobby and King, and the latter's by Adrian Cole and Roy Phillipps. Pickings were scarce and No. 4 Squadron's only success came on the second day when King and his flight collectively destroyed a two-seat Albatros.
On 16 August 1918, King participated in a major assault against the German airfield at Haubourdin, near Lille, that resulted in thirty-seven enemy aircraft being destroyed on the ground. During the action, described by the official history as a "riot of destruction", King set on fire a hangar housing four or five German planes. He also, according to No. 2 Squadron pilot Charles Copp, flew down Haubourdin's main street, waving as he went, his reason being that "the girls in that village must have had a heck of a time with all that bombing and must have been terribly scared so I thought I'd cheer them up a bit". By this time the Lille sector was largely clear of German fighters. The official history recorded that on 25 August, "King went out alone as far as Don railway station, bombed it, machine-gunned a train, and returned among the low clouds—all without seeing any enemy". The only contact around this time was on 30 August, when King, Thomas Baker and another pilot shot down two DFWs near Laventie. On 1 September, King destroyed an observation balloon over Aubers Ridge. Three days later he shot down an LVG after attacking a train near Lille with Cobby. He was recommended for the Distinguished Flying Cross (DFC) on 8 September. The award, promulgated in The London Gazette on 3 December, cited his "gallant and valuable service in bombing and attacking with machine gun fire enemy billets, trains, troops etc", during which "he ensure[d] success by descending to low altitudes, disregarding personal danger". On 16 September, following a lull in aerial combat in the region, King destroyed a Fokker biplane over Lille. Around this time he was promoted to captain and flight commander. He took over "A" Flight from Cobby, who had been posted to England. By the end of September, King's tally was eighteen. He registered his final victory in a Camel on 2 October, when he used bombs to send down his fourth balloon.
During October 1918, King converted with the rest of No. 4 Squadron to the upgraded Sopwith Snipe, whose larger cockpit was a better fit for him. He scored with the Snipe on both 28 and 29 October, the latter over Tournai, in what is frequently described as "one of the greatest air battles of the war". At Tournai, amid a confrontation involving over seventy-five Allied and German fighters, King evaded five enemy Fokkers that dived on him, before destroying an LVG in a head-on attack. The next day, he downed three Fokker D.VIIs, two without firing a shot. As he zoomed up from shooting one out of control, he cut off another. This second Fokker pulled up to avoid collision and toppled onto a third Fokker. One of the war's last air battles took place near Leuze on 4 November. King's destruction of two D.VIIs in the space of five minutes, the latter in flames, capped his combat career. His tally of seven victories with the Snipe in the closing days of the war made him the highest-scoring pilot in this type.
King's final wartime score of twenty-six included six aircraft driven down out of control, thirteen aircraft and four balloons destroyed, and three other aircraft destroyed in victories shared with other airmen. This made him second only to Harry Cobby as the most successful ace in the AFC, as well as the fourth most successful of all the Australian aces in the war (his top-scoring compatriots, Robert Little and Roderic (Stan) Dallas, flew with the British Royal Naval Air Service and Royal Air Force). King was recommended for a bar to his DFC, which was upgraded to the Distinguished Service Order and awarded on 3 June 1919. The recommendation noted his victories in the air and described him as having "proved himself a very brilliant patrol leader" and as "a magnificent example at all times to all pilots in the Squadron by his keenness on the ground and gallantry in the air which was of the highest possible order". He was also belatedly mentioned in despatches in July 1919 for his wartime service.
After the war had a career in commercial aviation, flying aircraft along Australia's east coast delivering letters and packages. In 1939 King signed up once again, joining the RAAF as a Squadron Leader, subsequently receiving a promotion to Group Captain. He worked at a series of training bases until his sudden death on 28 November 1941 in Point Cook, Australia.