Oskar Halecki [SEP] date of death
Oskar Halecki
Oskar Halecki (26 May 1891, Vienna – 17 September 1973, White Plains, New York) was a Polish historian, social and Catholic activist.
Life and career.
Halecki, whose first name is sometimes spelled Oscar in English-language sources, was born in Vienna to a Polish officer serving in the Austrian army. His father, Oscar Chalecki-Halecki, achieved the rank of Lieutenant Field-marshal. His mother was Leopoldina deDellimanic.
After graduating with a doctorate from the Jagiellonian University
substantially by the marriages. A woodcut by Albrecht Dürer commemorates the double wedding on 22 July 1515. 
Vladislaus died on 13 March 1516, and Maximilian died on 12 January 1519, but his designs were ultimately successful: on Louis's death in 1526, he was succeeded as King of Bohemia by Maximilian's grandson, Ferdinand I, Holy Roman Emperor.
References.
- "Borderlands of Western Civilization: A History of East Central Europe", Oskar Halecki, 1952. .