Last week, reports indicated Stefan Halper, a Cambridge professor and longtime aide to some of Washington’s most powerful figures, was outed as an FBI informant planted inside Donald Trump’s 2016 presidential campaign.

The New York Post writes:

Halper made his first overture when he met with Page at a British symposium. The two remained in regular contact for more than a year, meeting at Halper’s Virginia farm and in Washington, DC, as well as exchanging emails. The professor met with Trump campaign co-chair Sam Clovis in late August, offering his services as a foreign-policy adviser, The Washington Post reported Friday, without naming the academic. … Days later, Halper contacted Papadopoulos by e-mail. The professor offered the young and inexperienced campaign aide $3,000 and an all-expenses-paid trip to London, ostensibly to write a paper about energy in the eastern Mediterranean region.

Here are a few fast facts about Halper’s history in politics.

Got His Start in Nixon/Ford Years

The Stanford and Oxford-educated Halper started his career in government in 1971 as a member of President Richard Nixon’s Domestic Policy Council. The foreign policy expert served as the Office of Management and Budget’s Assistant Director of Management and Evaluation Division between 1973-1974. Halper then served as an assistant to all three of President Gerald Ford’s Chief of Staffs — Alexander Haig, Donald Rumsfeld, and Dick Cheney — until 1977.

Accused of Leading a Spy Ring Inside Jimmy Carter’s Presidential Campaign

The Reagan-Bush presidential campaign hired Halper to serve as Director of Policy Coordination in 1980 and would later be embroiled in the Debategate affair, a scandal in which CIA operatives were accused of leaking the Carter campaign’s foreign policy positions to the Republican ticket.

The Intercept’s Glenn Greenwald reports:

Four decades ago, Halper was responsible for a long-forgotten spying scandal involving the 1980 election, in which the Reagan campaign – using CIA officials managed by Halper, reportedly under the direction of former CIA Director and then-Vice-Presidential candidate George H.W. Bush – got caught running a spying operation from inside the Carter administration. The plot involved CIA operatives passing classified information about Carter’s foreign policy to Reagan campaign officials in order to ensure the Reagan campaign knew of any foreign policy decisions that Carter was considering.

Halper also worked as Deputy Assistant Secretary of State for Political-Military Affairs during President Ronald Reagan’s first term.

Had a Stint as a Bank Executive

In 1984, Halper was chairman of three financial institutions — National Bank of Northern Virginia, Palmer National Bank, and George Washington National Bank. White House official Oliver North wired loaned funds from the Palmer National Bank to a Swiss bank account, which were later used to aid the contras.

Believed Hillary Clinton Would Be a Better Steward for U.S.-UK Relations

In March 2016, Halper told Russia’s Sputnik News that he believed then-Democratic presidential nominee Hillary Clinton would prove to be a steadier hand in preserving the “special relationship” enjoyed by the United States and Britain.

“I believe Clinton would be best for US-UK relations and for relations with the European Union. Clinton is well-known, deeply experienced and predictable. US-UK relations will remain steady regardless of the winner although Clinton will be less disruptive over time,” Halper said.