Brigadier Halsted joined the Royal Marines in 1999, having graduated from Cambridge University in Natural Sciences. He joined 3 Commando Brigade as a Troop Commander, deploying to Northern Ireland for the very last weeks of military patrolling.
As a junior officer, Brig. Halsted specialized in surveillance and reconnaissance, serving in Bosnia and running a specialist British Army training team and preparing troops for operations in Iraq, Afghanistan and Kosovo.
As a Major, he served at staff in Afghanistan and in equipment capability. In 2012, he commanded a combat company at 42 Commando Royal Marines, exercising in arctic Norway and California’s desert as well as providing military support to the London Olympics. A second command tour involved partnering Afghan security forces in Kabul and Kandahar.
On promotion to Lt Col., he attended the UK’s Advanced Command and Staff Course, placing top of the course and gaining a master’s degree from King’s College London. His papers included Op BARBAROSSA, British and French strategy in the Peninsula War and the implications of human nature for international relations theory.
At O4 staff, he served as Military Assistant to the UK’s Defence Senior Advisor to the Middle East (the UK's regional ‘military diplomat’). Over 2017-2019, Halsted commanded 42 Commando, consolidating its role as a specialist maritime operations unit as part of the redesign of UK Commando Forces.
At O5, he served first as operations chief in HQ Special Forces, overseeing novel and cutting-edge global operations. In early 2022 he attended the UK’s Higher Command and Staff Course for future senior leaders. Most recently, Brig. Halsted served in the Ministry of Defence’s strategic staff, covering homeland operations and as the 1* military head of the Counter-Violent Extremist Organisations Campaign Team.
He is married to Annabel (an investment banker and the family breadwinner) and has a 3-year-old son Freddie. Brig. Halsted is an aficionado of rugby, kayaking, skiing and martial arts. He plays the bass guitar and is an enthusiastic but inexpert participant in a spread of other sporting and outdoor pursuits.
Brig. Halsted assumed the appointment of Deputy Commanding General Operation Inherent Resolve in November 2023.