Pilgrim Days: From Vietnam to the SAS by Alastair MacKenzie is a memoir of the author who served in the special forces of several countries over his life. The book documents his life from serving in the New Zealand Army in Vietnam, to the SAS, South Africa, Oman, and finally as a private security agent.

It’s surprising that I’ve never heard of this man, a legend then & now as well since much of the Special Forces methodology today is based on his methods.