1935) was an Austro-Hungarian diplomat of Hungarian origin serving in various posts including as an envoy to Greece during World War I and, for many years, as Secretary of the Austro-Hungary Legation to Washington, D.C.[1] He was a direct descendant of the British Hope family which owned the famous Hope Diamond.
[2][better source needed] They had one child, Charles Henry de Szilassy who was born December 15, 1899, Detroit, Wayne Michigan.
In 1907, Szilassy was a member of the Austro-Hungarian delegation to the Second Hague Peace Conference and was appointed the following year to serve as counsellor in St. Petersburg before returning to Vienna in 1912.
As one of few professional diplomats who remained in service following the fall of the Habsburg Empire in 1918, he served as the first Hungarian envoy to Switzerland from February to April 1919.
After Béla Kun's revolution, he went into exile but did not return to Hungary during the Horthy years and devoted his remaining life to write several books on diplomacy as well as his memoirs.