LONDON — Peter Ramsbotham, who served as Britain’s ambassador to Washington during the Watergate era, died Friday, his family said. He was 90.

Zaida Ramsbotham said her husband died of pneumonia at their family home in the village of Ovington in southern England.

Educated at Eton and Oxford, Ramsbotham served in the British Intelligence Corps during and after World War II, ferreting out German spies and former Nazis. He joined Britain’s Foreign Office in 1948, serving in Berlin and at the United Nations in New York before being promoted to High Commissioner in Cyprus to 1969.

Ramsbotham served as ambassador to Iran from 1971 to 1974 before moving on to the United States. The ambassador would stay on through the administrations of Richard Nixon, Gerald Ford and Jimmy Carter.