Ian Thomson was the son of John Alex Thomson and of Margaret Anne Thomson (nee Madill) of Auckland.

Wounded in fighting at El Mreir on 15 July 1942. He recorded in his diary that he was wounded and taken out 1500 hrs with the Company Commander and 4 men of his unit to the Advanced Dressing Station and from there to No. 1 British General Hospital before moving to No. 2 New Zealand General. In all he spent three months recovering. "During the time Abbott was away [at Headquarters 4 Brigade seeking permission to move C Company to where the remainder of the battalion was dug in] Captain Wallace realised that his party was in the centre of a minefield and thought it advisable to move further forward. Some trenches were located in a small wadi about 400 yards ahead and, with enemy shells exploding the mines around them, he ordered an advance into the shelter of the wadi. Both Wallace and Lieutenant Thomson were wounded in helping some half-buried men out of a trench...' (21 Battalion Official History, p. 180.)

He died in the fighting that took place in Castelfrentano in December 1943 which was part of the battle taking place around the Sangro river area in the Eighth Army's move up the Adriatic coast of Italy. Intense and bitter fighting marked this stage of the campaign as the Germans strove to hold what was known as their 'Winter Line'.

Major Thomson had taken over B Company of 24 Battalion by the time they reached Italy in early October. The action in which he died was part of a move by 5 and 6 Brigades towards Orsogna. From 2 December C Company had occupied the most advanced position closest to Orsogna. On 7 December about 1 pm B Company joined them. An attack was to begin later that afternoon. Once the bombardment began the two companies, lead by Majors Thomson and Clarke, moved forward under concentrated shell and mortar fire. 'About three o'clock a shellburst killed Major Thomson... close by the Pink House on the town's outskirts'. Major Clarke was wounded in the same action and died as a result. Both are buried at Sangro River Cemetery.

The Auckland Museum Library's manuscripts collection holds a typed transcript of Thomson's war diary. It covers a period from 2 September 1939 until 22 November 1943, approximately two weeks before he died, and contains details of his training, units, leave and promotions as well as references to other officers, including the E.S. Clarke referred to above. [Ref. MS 2002/152] AWMM