Matthew Maer was deployed to Iraq in 2004 as lieutenant colonel of the Princess of Wales Royal Regiment, and was promoted to colonel and brigadier after receiving an award.
Maer commanded the 1st Battalion, Princess of Wales's Royal Regiment as a lieutenant colonel, deploying to Maysan, Iraq in 2004 in the aftermath of the invasion of Iraq. In this role, he was awarded the Distinguished Service Order for his leadership, which included command of Victoria Cross recipient Johnson Beharry. Maer was promoted colonel on 30 June 2006, and brigadier on 30 June 2009. 
