Hungarian president Pal Schmitt is resigning after a row over plagiarism in a university doctorate he got almost 20 years ago.
Mr Schmitt, elected in 2010 for a five-year term, said he was stepping down because his "personal issue" is dividing Hungary.
Mr Schmitt's 1992 doctoral thesis was revoked last week after an investigation found that most of it was copied from two other authors.
Mr Schmitt told parliament: "In this situation, when my personal issue divides my beloved nation instead of uniting it, I feel it to be my personal duty to finish my service and resign from my presidential mandate. I ask God's blessing for Hungary and for your work."
Mr Schmitt, 69, then quickly left the chamber accompanied by prime minister Viktor Orban as MPs gave him a standing ovation.
The resignation comes at a turbulent time in Hungarian politics. Mr Orban, who had made his name by protesting Hungary's communist dictatorship, is now being criticised for pushing the nation toward centralised rule.
The European Union, which Hungary joined in 2004, has criticised legislation Mr Orban's party passed for limiting democratic principles such as freedom of the press and an independent judiciary and central bank.
Mr Schmitt had been elected president with support of Mr Orban and his Fidesz party. Last week, Mr Schmitt's 1992 doctorate was revoked after a university committee, following up on a report published in January by the internet publication HVG.hu, found that most of his thesis about the modern Olympic Games had been copied from the work of two other authors.
Mr Schmitt won two gold metals at the 1968 and 1972 Olympics on his country's fencing teams.
His resignation came a day after he told state radio he would not step down. But pressure on him quickly grew, even among intellectuals and media close to Mr Orban's government.