AJEX archivist Martin Sugarman ensures Jewish war grave errors are corrected.

A new plaque commemorates cryptographer Leopold (Leo) Marks MBE at Kendal Road, Marble Arch.

It is positioned near the entrance to flats where Leo lived when he was Chief of Codes at Special Operations Executive (SOE) in Baker Street during World War Two.

Jerry Klinger of The Jewish American Society for Historic Preservation, UK branch, commissioned the initiative.

Leo was born in 1920 and headed the coding office supporting resistance agents in Europe.

Born into a devout Jewish family in London, his father, Benjamin Marks worked at ’84 Charing Cross Road’ bookshop featured in a Hollywood film. Here Leo deciphered price codes pencilled inside book covers by his father.

Called up in 1942 his coding skill reached SOE headed by Sir Charles Hambro.

Leo briefed agents including secret agent F.F.E Yeo Thomas along with Jewish agents including Denise Bloch, Marcus Bloom, Isidore Newman and Muriel Byck. Supreme Allied Commander General Eisenhower said SOE shortened the war and saved countless lives.

Among Leo’s innovations were code poems and one-time pad. Both increased code security in radio messages for agents. Among his poems was the classic Violette Szabo, ‘The Life That I Have’.

Leo also discovered that most Dutch agents were compromised. His actions saved lives.

Post War, Leo wrote plays, films and a book about his life, ‘Between Silk and Cyanide’.

Sugarman interviewed him before he died in 2001.

Anyone suspecting a headstone is incorrect contact Martin 07806 656756.