Dennis Martin started training in Karate in 1965. In 1970 he started working with Terry O'Neill on the door of a Liverpool nightclub. In 1973 he went to Japan and Okinawa to train in Goju-ryu Karate for 6 months. On returning to England in October 73 he was asked to be a bodyguard at the Miss World Contest, specifically providing protection for Miss Israel. This led him to further training and work in the field of VIP Protection. He has worked as a team leader and operator on VIP protection tasks for several Royal families and Diplomatic entities. In 1985 he formed CQB Services, a training company, and offered the first ever commercial close-protection training course in the UK. Together with Lofty Wiseman, he trained bodyguards from Europe, Australia, USA and Africa.
Based on the methods taught to the bodyguards, he started teaching Close Quarter Battle [CQB] techniques to security, police and civilian personnel. For self-protection, rather than the traditional martial art of Karate, he developed an efficient, practical curriculum of Combatives based on his experience on Liverpool nightclub doors. According to Geoff Thompson "Dennis Martin is the most credible instructor of real self-defence in the world today"
His book "Working with Warriors" was published in 2008.