I never knew anything of any significance about the SAS except what's in popular film/culture. I picked up this book on a whim, and it's now one of my favorites. Extremely well-written, it reads almost like a novel, but the author clearly researched the material. The fact that the SAS got traction much less sustained through WWII is incredible, and what Sterling did and how he operated to keep it afloat was stuff of legend. There were some tragedies--many tragedies--hubris, over-confidence, poorly-planned ops--which should never have happened, but the things that went well were incredible.