Peter Cottrell was born on an RAF base in Norfolk to Welsh parents and grew up in South Wales. He joined his local Welsh Territorial Army infantry battalion whilst still at school and subsequently gained a degree in War Studies from Wolverhampton Polytechnic and a PGCE from University College Swansea. In 1988 he attended Britannia Royal Naval College and was commissioned into the Instructor Branch of the Royal Navy as a Defence and Political Studies specialist. After a period of loan service in Saudi Arabia he transferred to the British Army in 1995 and gained a Master's degree in History, specialising in the militarisation of policing in Ireland from 1913-23. In an eclectic service career that included operational service in Bosnia with both UNPROFOR and IFOR as well as Afghanistan, Iraq and Northern Ireland, he finally retired as a major after twenty-one years of naval and military service in 2008 to return to teaching. From 2008-16 he taught English, History, Latin and Classics in Wiltshire and then moved to Cumbria in 2016 to be head of English and Media in a small secondary school in the depths of rural Cumbria. In 2021 he finally retired to live on the Yorkshire coast.