As pleased as Punch
'As pleased as Punch' derives from the puppet character Mr. Punch. Punch's name itself derives from Polichinello (spelled various ways, including Punchinello), a puppet used in the 16th century Italian Commedia dell'arte.
Punch and Judy shows, the popular summer-time entertainments on British beaches, have been somewhat in decline from the latter half of the 20th century onward, due to them being seen as politically incorrect. That's hardly surprising as the main character Punch is a wife-beating serial killer.
In performance, the grotesque Punch character is depicted as self-satisfied and delighted with his evil deeds, squawking "That's the way to do it!" whenever he dispatches another victim. Nevertheless, there is still what might be called a folk affection for the old rogue in the UK and it would be a shame to see the tradition fade away completely.
The show had an Italian origin but has been much changed over the years. It began in Britain at the time of the restoration of the monarchy in the 17th century. The Diary of Samuel Pepys has an entry from 1666 that shows this early origin and also the popularity of the show even then:
I with my wife... by coach to Moorefields, and there saw ‘Polichinello’, which pleases me mightily.
The phrase 'as pleased as Punch' appears fairly late in the story. The earliest known record is from William Gifford's satires The Baviad, and Maeviad, 1797:
Oh! how my fingers itch to pull thy nose! As pleased as Punch, I'd hold it in my gripe.
'As pleased as Punch' is now the most common form of the expression, but when the term was coined it was just as usual to say 'as proud as Punch'. Charles Dickens, for example used the two terms interchangeably in his novels; for example:
David Copperfield, 1850: I am as proud as Punch to think that I once had the honour of being connected with your family.
Hard Times, 1854: When Sissy got into the school here.. her father was as pleased as Punch.
See other 'as x as y' similes.