Edward Heath defeated two rivals to become leader of the Conservatives on this day in 1965, in a leadership contest brought about by the unexpected resignation of his predecessor, Sir Alec Douglas-Home.

The result was something of a surprise, as the shadow Chancellor of the Exchequer had been considered an underdog in the battle to replace Mr Douglas-Home to Reginald Maudling. In the event, Mr Heath won the votes of 150 Tory MPs to the 133 who backed shadow Foreign Secretary Mr Maudling.

Another candidate, shadow Transport Minister Enoch Powell, who had not expected to win but said he had “left his calling card”, polled 15 votes.

Under Conservative Party rules at the time, a candidate had to win an overall majority of votes, as well as a lead of at least 15% in votes cast, excluding abstentions. Mr Heath’s majority satisfied the first criterion, but failed to achieve the second; nevertheless, Mr Maudling (pictured below) withdrew without demanding a second ballot.

Reginald Maudling, former Chancellor of the Exchequer, who was beaten by Heath in the poll.

Until this point, the selection of the leader of the Conservatives had been decided by a consultative process carried out by the parliamentary party, but the selection of Mr Douglas-Home in 1963 had led to such disquiet that the outgoing leader had put in place new rules to ensure his successor would be chosen by ballot.

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Mr Heath had fought a vigorous campaign managed by future Conservative minister Peter Walker, which was fuelled by recent acclaim for his opposition to Labour’s Finance Bill. Mr Maudling may have suffered for an underwhelming performance as Chancellor in the last Tory government.

Though immediately installed as the new party leader, Mr Heath was formally inducted into the role a week later as he made a traditional address to a meeting of Young Conservatives, Tory peers, the party's national executive and constituency delegates.