Hungary's President Pal Schmitt says he is resigning, after being stripped of his doctorate over plagiarism.
Mr Schmitt, elected in 2010, said "my personal issue divides my beloved nation rather than unites it".
"It is my duty to end my service and resign my mandate as president," he told parliament.
Last week, Budapest's Semmelweis University revoked his 1992 award after finding that much of his thesis had been copied.
Mr Schmitt, 69, won gold medals for fencing at the 1968 and 1972 Olympic Games.
He was elected to the largely ceremonial role of president for a five-year term, with strong backing from the conservative ruling Fidesz party of Prime Minister Viktor Orban.
The university said whole passages of his thesis about the modern Olympic Games had been copied from the work of two other academics.
He denied wrongdoing and resisted calls for him to go, but on Saturday protesters in Budapest stepped up the pressure for him to resign.
Mr Schmitt served as Hungary's ambassador to Spain in 1993-1997, and to Switzerland in 1999-2002.