In March 1939, Robertson was appointed commander of the 7th Military District, which encompassed the Northern Territory.
It was his first command since the First World War.
He was promoted to the temporary rank of colonel in August 1939, and this became substantive in November.
The job involved cooperation with the Royal Australian Navy and Royal Australian Air Force, and the administration of a company of regular soldiers known as the Darwin Mobile Force.
After the Second World War began in September 1939, Robertson became responsible for supplying the 7th Military District's quota of volunteers for the Second Australian Imperial Force (AIF).
A strike on the waterfront saw Robertson committing troops to help unload cargo.

On 4 April 1940, Robertson joined the Second AIF himself, with the rank of brigadier, and was allocated the AIF service number VX20321.
He was appointed to command the 19th Infantry Brigade, which was then being formed from units made surplus by the reduction of the 6th Division from 12 infantry battalions to nine.
All three of its battalions, the 2/4th, 2/8th and 2/11th Infantry Battalions, were initially commanded by over-age officers, but the commander of the 2/4th was replaced by Ivan Dougherty in August.
Initially, Dougherty received a cool reception from Robertson, who was disappointed at being unable to select his own battalion commanders, but Dougherty soon made such a good impression that when Robertson went on leave in October 1940 he recommended that Dougherty act as brigade commander, despite the fact that he was the youngest and most junior of Robertson's battalion chiefs.

The Battle of Bardia brought to the fore the simmering hostility between regular officers and reservists.
Frank Berryman, the 6th Division's General Staff Officer (Grade 1), and Alan Vasey, the Deputy Assistant Adjutant and Quartermaster General (DA&QMG), were eager for Robertson to do well and show that Staff Corps officers could make good commanders, and if that could be done at the expense of an old-style reservist like Stanley Savige, so much the better.
They pushed for Robertson's 19th Infantry Brigade, then in reserve, to be committed when the attack by Savige's 17th Infantry Brigade slowed down.
The abrupt manner in which this was done generated antipathy between Robertson and Savige.

The 19th Infantry Brigade then advanced on Tobruk.
The attack on this fortified town proceeded along similar lines to that on Bardia, with the 16th Infantry effecting a break-in of the position, but this time the 19th Infantry Brigade was to carry out the exploitation phase.
Robertson's contribution to the plan was to increase its tempo, so that the attack would be carried through without pause, the exploitation being carried out before the initial break-in was complete.
Robertson accepted the surrender of the fortress commander, Generale di Corpo d'Armata Pitassi Mannella, and later Admiral Massimiliano Vietina, the Italian naval commander.
Comments by "a sunburnt red-headed Australian brigadier" made headlines in Britain, where senior officers rarely spoke to the media, but did not endear Robertson to his critics, who felt that his ego was out of control.
Following the entry of the 19th Infantry Brigade to Benghazi on 7 February, Robertson declared "give me two stout ships and a bearing on Rome and we'll dine in the hall of the caesars".

For this campaign, Robertson was made a Commander of the Order of the British Empire (CBE), but later that month he was hospitalised for varicose veins in the leg he had broken in 1917.
He was replaced as commander of the 19th Infantry Brigade by Alan Vasey.
When Robertson recovered he was given responsibility for the training of AIF reinforcements in the Middle East.
Robertson's service in the field and his long experience in training troops made him an ideal candidate for the post.
For his services, Robertson was mentioned in despatches a third time.
In March 1939, Robertson was appointed commander of the 7th Military District, which encompassed the Northern Territory. It was his first command since the First World War. He was promoted to the temporary rank of colonel in August 1939, and this became substantive in November. The job involved cooperation with the Royal Australian Navy and Royal Australian Air Force, and the administration of a company of regular soldiers known as the Darwin Mobile Force. After the Second World War began in September 1939, Robertson became responsible for supplying the 7th Military District's quota of volunteers for the Second Australian Imperial Force (AIF). A strike on the waterfront saw Robertson committing troops to help unload cargo.
On 4 April 1940, Robertson joined the Second AIF himself, with the rank of brigadier, and was allocated the AIF service number VX20321. He was appointed to command the 19th Infantry Brigade, which was then being formed from units made surplus by the reduction of the 6th Division from 12 infantry battalions to nine. All three of its battalions, the 2/4th, 2/8th and 2/11th Infantry Battalions, were initially commanded by over-age officers, but the commander of the 2/4th was replaced by Ivan Dougherty in August. Initially, Dougherty received a cool reception from Robertson, who was disappointed at being unable to select his own battalion commanders, but Dougherty soon made such a good impression that when Robertson went on leave in October 1940 he recommended that Dougherty act as brigade commander, despite the fact that he was the youngest and most junior of Robertson's battalion chiefs.
The Battle of Bardia brought to the fore the simmering hostility between regular officers and reservists. Frank Berryman, the 6th Division's General Staff Officer (Grade 1), and Alan Vasey, the Deputy Assistant Adjutant and Quartermaster General (DA&QMG), were eager for Robertson to do well and show that Staff Corps officers could make good commanders, and if that could be done at the expense of an old-style reservist like Stanley Savige, so much the better. They pushed for Robertson's 19th Infantry Brigade, then in reserve, to be committed when the attack by Savige's 17th Infantry Brigade slowed down. The abrupt manner in which this was done generated antipathy between Robertson and Savige.
The 19th Infantry Brigade then advanced on Tobruk. The attack on this fortified town proceeded along similar lines to that on Bardia, with the 16th Infantry effecting a break-in of the position, but this time the 19th Infantry Brigade was to carry out the exploitation phase. Robertson's contribution to the plan was to increase its tempo, so that the attack would be carried through without pause, the exploitation being carried out before the initial break-in was complete. Robertson accepted the surrender of the fortress commander, Generale di Corpo d'Armata Pitassi Mannella, and later Admiral Massimiliano Vietina, the Italian naval commander. Comments by "a sunburnt red-headed Australian brigadier" made headlines in Britain, where senior officers rarely spoke to the media, but did not endear Robertson to his critics, who felt that his ego was out of control. Following the entry of the 19th Infantry Brigade to Benghazi on 7 February, Robertson declared "give me two stout ships and a bearing on Rome and we'll dine in the hall of the caesars".
For this campaign, Robertson was made a Commander of the Order of the British Empire (CBE), but later that month he was hospitalised for varicose veins in the leg he had broken in 1917. He was replaced as commander of the 19th Infantry Brigade by Alan Vasey. When Robertson recovered he was given responsibility for the training of AIF reinforcements in the Middle East. Robertson's service in the field and his long experience in training troops made him an ideal candidate for the post. For his services, Robertson was mentioned in despatches a third time.
Horace Robertson