As Vice Chief of the General Staff from 8 January 1946 to 16 April 1950, he played a key role in the post-Second World War reorganisation of the Army, and in the 1949 Australian coal strike.

Rowell was educated at Adelaide High School and was one of the first cadets to enter the Royal Military College, Duntroon when it opened in 1911.

For a time it looked like Rowell would again miss the embarkation of his regiment, but the intervention of his father ensured that he reached Anzac Cove with the 3rd Light Horse on 12 May 1915.

[11] Rowell was promoted to the temporary rank of captain on 9 September, briefly assuming command of a squadron before becoming the regimental adjutant three days later.

[12] On 20 August 1919 at the Chalmers Church, North Terrace, Adelaide, Rowell married Blanche May Murison,[1] the daughter of a Scottish engineer.

Qualifying in first place gave him a choice between the Staff College, Camberley and its counterpart at Quetta, and Rowell chose the former, attending from 1925 to 1926.

[17] Rowell returned to Australia to become Director of Military Operations and Intelligence at Army Headquarters in Melbourne but in August 1938 he became staff officer to the Inspector General, Lieutenant General Ernest Squires,[2] partly because Rowell was recognised as "one of the ablest of the early Duntroon graduates" but also because he had spent five of the previous thirteen years with the British Army or at British staff colleges.

The death of Prime Minister Joseph Lyons in April 1939 and his subsequent replacement by Robert Menzies caused this to be shelved.

[20] Gavin Long described Rowell as "clear and incisive in thought, sensitive in feeling, frank and outspoken in approach to men and to problems.

Five recent years of service either at English staff colleges or on exchange duty made it probable that wherever he went his opposite numbers in British formations would be men with whom he had previously worked and played."

Comparing him to the AA&QMG, Colonel George Alan Vasey, Long noted that both "were not only efficient soldiers but men of commanding temperament and talent".

[21] Blamey and Rowell prepared I Corps for operations as best they could, completing the force's structure and integrating new units as they arrived in the Middle East.

[22] Rowell strove to establish good relations with the British Army, while occasionally having to remind them that the AIF was answerable to its own commander in chief and its own government.

[23] Rowell's efforts to create an administrative headquarters to free the I Corps staff for operational duties foundered on Blamey's reluctance to delegate authority.

[22] The best that he could achieve was the creation of a Base and Line of Communications Units command under Brigadier Allan Boase but I Corps remained responsible for organisation and training.

[28] Blamey and his staff worked under tremendous pressure; the operational situation was precarious; and German air attacks were frequent.

Apparently, General Sir Henry Maitland Wilson believed that I Corps' loss of transport and signal equipment precluded it from participating in the campaign from the outset.

This proved to be a serious error, as his staff were preoccupied with political and administrative issues, and were too remote from the battlefields to exercise the close command required—something that Rowell foresaw.

[36] He expected that his main task would be to support the AIF; but it turned out the primary concern was the looming war with Japan, which broke out soon after.

A heated argument ensued, ending with Rowell telling Vasey that "if he weren't so bloody big, I'd toss him out of the room".

[41] Rowell arrived in Port Moresby on 13 August 1942 and assumed command of New Guinea Force from Major General Basil Morris.

[46] Rowell's staff gradually discovered how enormous the task before them was; they had few maps, the only transport aircraft were destroyed in a Japanese raid, and the supplies that had been forwarded by air to Kokoda could not be located.

[48] Failure to keep GHQ up to date could only lead to fears of the worst, which were confirmed when Major General George Kenney reported that in his opinion Port Moresby would soon fall unless something drastic was done, and Rowell was "defeatist".

Blamey wrote a letter to Rowell to explain the situation in advance of his arrival in Port Moresby on 23 September: The powers that be have determined that I shall myself go to New Guinea for a while and operate from there...

I think it arises out of the fact that we have very inexperienced politicians who are inclined to panic on every possible occasion, and I think that the relationship between us personally is such that we can make the arrangement work without any difficulty.

He wrote to Major General Cyril Clowes at Milne Bay: The plain fact is that he [Blamey] hasn't enough moral courage to fight the Cabinet on an issue of confidence in me.

[53]On 25 September, at MacArthur's suggestion, Blamey flew to Milne Bay with Brigadier General Kenneth Walker and ordered Clowes to send a force by air to Wanigela.

Re disposal of Rowell if you decide to continue his services he could replace Herring in command of II Corps but events here make me doubtful of wisdom of allocating disgruntled officer to this appointment.

[62] In December 1943, Rowell took up the appointment as Director of Tactical Investigation at the War Office in London vice Lieutenant General Alfred Reade Godwin-Austen at the instigation of Richard Casey.

[75] For his services as Chief of the General Staff, Rowell was created a Knight Commander of the Order of the British Empire in the Queen's Birthday Honours in 1953.