Brigadier Aubertin Walter Sothern Mallaby CIE OBE (12 December 1899 – 30 October 1945) was a British Indian Army officer who was killed in a shootout during the Battle of Surabaya in what was then the newly proclaimed as independent Republic of Indonesia during the Indonesian National Revolution.

Mallaby's death became a major event of hostilities in Surabaya surrounding Indonesian independence, triggering a retaliatory military action by the 5th Indian Infantry Division.

[1] Mallaby was born to actor and acting company manager William Calthorpe Mallaby (né William Calthorpe Deeley- his father insisted on a stage name;[2] d. 1912) and Katharine Mary Francis, daughter of George Miller, CB, Assistant Secretary of the Board of Education (son of Rev.

He was appointed an Officer of the Most Excellent Order of the British Empire OBE as Major, temporary Lt-Col, acting Brigadier.

[13] Mallaby was appointed a Companion of The Most Eminent Order of the Indian Empire in the London Gazette of 1 January 1945 as a temporary Brigadier.

[15] However, the situation became more heated on 27 October after Mallaby interpreted pamphlets demanding the immediate surrender of the Indonesians' weapons, signed by General Douglas Hawthorn, as an order.

To quench the fighting, Mallaby was able to contact General Hawthorn through an intermediary and arrange a meeting between himself and President Sukarno, where they negotiated a ceasefire.

Fearing that their commander was about to be attacked, the British troops in the International building, led by Major Venu K. Gopal, fired into the air to disperse the Indonesian militia.

The top republicans however, were displeased to learn of the attack on Mallaby, knowing that his death may result in dire consequence to Surabaya and its residents.

Local Surabaya historian Ady Erlianto Setyawan also confirmed that the possibility of Abdul Aziz being the killer was high, since the claim is also supported by testimony of the last known witness present on the killing site, a Republican journalist of Arab descent, Amak Altuwy.

[20][21] Mallaby married Margaret Catherine Jones (known as Mollie) on 9 April 1935 at St Mark's Church, North Audley Street, London.