The Enigma Symposium 1999

The Enigma Symposium 1999 is Hugh Skillen's self-published record of the sixth Enigma Reunion, issued as an oversized softcover with glossy green covers.

Running to 210 pages, it continues the format of Skillen's earlier symposium volumes: firsthand wartime testimony from veterans of Bletchley Park and the Y Service's signals intelligence work, illustrated throughout with black-and-white photographs. A color photograph near the front of the book shows the author and fellow veterans at the Imperial War Museum in 1997.

Skillen, a former Intelligence Corps officer, wrote the trilogy Spies of the Airwaves (1989), Knowledge Strengthens the Arm (1990), and Enigma and Its Achilles Heel (1992) documenting the Army's Y Service before turning to the Enigma Reunions, which he convened and published proceedings for annually through the 1990s.