<human>: Answer by taking a quote from the following article:

Hugh Redwald Trevor-Roper, Baron Dacre of Glanton, FBA (15 January 1914 - 26 January 2003), was a British historian of early modern Britain and Nazi Germany. He was Regius Professor of Modern History at the University of Oxford. Trevor-Roper was made a life peer in 1979 on the recommendation of Prime Minister Margaret Thatcher, choosing the title Baron Dacre of Glanton. Trevor-Roper was a polemicist and essayist on a wide range of historical topics, but particularly England in the 16th and 17th centuries and Nazi Germany.

In 1980 at the age of 67, he became Master of Peterhouse, the oldest and smallest college in the University of Cambridge. His election, which surprised his friends, was engineered by a group of Fellows led by Maurice Cowling, then the leading Peterhouse historian. The Fellows chose him because Cowling's reactionary clique thought he would be an arch-conservative who would oppose the admission of women. In the event, Trevor-Roper feuded constantly with Cowling and his allies, while launching a series of administrative reforms. Women were admitted in 1983 at his urging. The British journalist Neal Ascherson summarised the quarrel between Cowling and Trevor-Roper as:  Lord Dacre, far from being a romantic Tory ultra, turned out to be an anti-clerical Whig with a preference for free speech over superstition. He did not find it normal that fellows should wear mourning on the anniversary of General Franco's death, attend parties in SS uniform or insult black and Jewish guests at high table. For the next seven years, Trevor-Roper battled to suppress the insurgency of the Cowling clique ("a strong mind trapped in its own glutinous frustrations"), and to bring the college back to a condition in which students might actually want to go there. Neither side won this struggle, which soon became a campaign to drive Trevor-Roper out of the college by grotesque rudeness and insubordination.  In a review of Adam Sisman's 2010 biography of Trevor-Roper, the Economist wrote that picture of Peterhouse in the 1980s was "startling", stating the college had become under Cowling's influence a sort of right-wing "lunatic asylum", who were determined to sabotage Trevor-Roper's reforms. In 1987 he retired complaining of "seven wasted years." CANNOTANSWER

What did he accomplish as Master of Peterhouse?
<bot>: Women were admitted in 1983 at his urging.