Dan grew up in Nottingham and went to Rushcliffe Comprehensive School. He graduated from Aberystwyth University with a degree in International Politics and Strategic Studies before attending the Royal Military Academy Sandhurst. From Sandhurst he was commissioned into The Parachute Regiment and subsequently deployed to Kosovo, Northern Ireland, briefly to Sierra Leone, and on numerous occasions to Iraq and Afghanistan. His service included: Platoon Commander with 1 Para, Aide de Camp to General Sir Mike Jackson, Adjutant of 3 Para, and on promotion to Major he worked as a staff planner in the Permanent Joint Headquarters (Northwood) and then at the Army’s Headquarters (Salisbury). He also served as a Company Commander in the Special Forces Support Group (St Athan).

In January 2011 he became the first person since World War Two to resign his commission in order to contest a parliamentary by-election. He was elected to Parliament on 3 March 2011, increasing the majority despite the reduced turn out that comes from a by-election. He was subsequently awarded the MBE for his service in the Army, which made him the first serving MP to be decorated for military service in many years.