The Earl of Derby
Edward George Geoffrey Smith-Stanley, 14th Earl of Derby KG PC, known before 1834 as Edward Stanley, and from 1834 to 1851 as Lord Stanley, had a really weird career. The longest ever serving leader of the Conservative Party he was Prime Minister three times (something only three other Prime Ministers ever matched), but his total time as Prime Minister was just over 4 years and none of his stints were longer than 2 years, making him one of the most frequent PMs and a fairly short term incumbent.
The first ministry was literally a few months and is known as The "Who? Who?" Ministry. Lord Derby was the Prime Minister and Benjamin Disraeli served as Chancellor of the Exchequer. It was also first time the Protectionist wing of the party had taken office since the Corn Laws schism of 1846. Ultimately however it was doomed. There were almost no established names in the cabinet. So much so that the aging Duke of Wellington kept interrupting the announcing of the ministers in the house of lords by saying "Who? Who?" at the top of his voice.
In 1858, Derby formed another minority government when The Viscount Palmerston's first ministry collapsed. This was the government that brought India directly under British Rule rather than that of the East India Company. Then it fell apart.
In 1866 he was back after Earl Russell's second government fell apart. Yet again Disraeli was a big player. In fact historians tend to consider that the Derby governments were dominated by Disraeli. This was the government that passed the Second Reform act. In 1868 Derby retired and guess who took up the reigns.
Regarded by many as The Father of The Conservative Party.