The Tory party is one of the oldest political parties in the world, dating back to the 1670's.
After the restoration of Charles II, Members of Parliament began to naturally coalesc into two groups who argued with each other.
In particular they were arguing about who should be the successor to Charles II, who had no children of his own. Legally the throne should have gone to his brother the Duke of York, but a group in parliament resisted this because he was Catholic. An opposing group believed that the law had to be followed and the Duke of York should be crowned.
The arguments were so fierce that the groups started to fling insults at each other. The supporters of the Duke of York were called "Tories", which was an abbreviation of the Gaelic word Toraide, meaning "Irish thief" or "Irish sheep-stealer". This was the worst insult their opponents could fling at them, as the Irish were Catholic (post restoration England was fiercely protestant).
The Tories retaliated by calling the opponents of the Duke of York, "Whigs" which was short for "Whiggamore" which meant Scottish Cattle Driver/Scottish Country Bumpkin. (As the English Civil War spread to Scotland in 1648, the Whiggamores were the chief Scottish opponents to Charles I).
So basically the two main political parties in England got their names from insults that their opponents flung at them. (And amusingly these insults involved neighbours - the Irish and Scots).
This is a world away from current practice, where political parties name themselves after vaguely aspirational phrases. The oxymoron "Progressive Conservatives" comes to mind. Or President Macron's party, "En Marche!" which means "Onward!" (And yes, he actually put an exclamation mark after his party's name).
The Tories won the argument and the Duke of York became James II.
And over 347 years later, they till exist and are in fact currently in government. In the mid 19th century they changed their official name to "Conservatives", but their opponents prefer to use the old insult, usually with "scum" attached - as in "Tory Scum". In the picture below, a tory candidate had her car vandalised with the words:
The Tories themselves have embraced the name. At election time you even see placards and buttons saying "Vote Tory" - which of course literally means "Vote for the Thieves".
Which is honest at least. Perhaps that is the secret to their longevity.