The Crossworders, champions of series one, return to challenge the kings of series two, the Rugby Boys.

The cunning wiles of the Wheel Men (Rev Richard Coles, Adam Hart-Davis, and Grub Smith) take on the combined brains of the Larks (Michael Bywater, Sir Andrew Motion, and Stuart Maconie).

The Gamblers, the winners of series three, square up to the Epicureans, the winners of series four.

Undefeated champions of champions, the Crossworders, risk their reputation by confronting the awesome brainpower of the University Challengers, captained by the illustrious Alex Guttenplan.

The Treesome (Brian Sewell, Adam Hart-Davis, and Grub Smith) lock intellectual brains with the Larks (Michael Bywater, Sir Andrew Motion, and Stuart Maconie).

The cunning wiles of the Great Believers (Nick Hornby, Dame Joan Bakewell, and John Lloyd) take on the combined brains of the Free Speakers (Ian Hislop, Simon Singh, and John Sessions).

Eight seasoned Only Connect teams return to take part in a Connecting Wall mini-tournament.

The semi-finals and final of the mini-tournament, plus wall-solving tales from celebrity alumni.

Series 3 & 4 champions the Epicureans take on Series 1 & 2 champions the Crossworders.

A trio of Mastermind series winners take on Only Connect champions the Crossworders.

Eight seasoned Only Connect teams return to take part in a Connecting Wall mini-tournament.

The semi-finals and final of the mini-tournament featuring seasoned Only Connect teams, plus wall-solving tales from celebrity alumni.

The Cutters (Nick Hornby, Mark Gatiss, and Samira Ahmed) take on the combined wits of the Backhanders (Ian Hislop, Stephen Mangan, and Allison Pearson).

The cunning wiles of the Goldfingers (Charlie Higson, Daisy Goodwin, and Matthew Parris) take on the combined brains of the Fowls (Rosie Boycott, Richard Osman, and Clarke Carlisle).

Series 5 champions the Analysts take on Series 6 champions the Scribes in a bid to be named Only Connect Champion of Champions.

Three Eggheads take on three champion captains all called David.

The Neuromantics (Charlie Higson, Rufus Hound, and Baroness Susan Greenfield) take on the combined wits of the Muppets (David Mitchell, Rosie Boycott, and Bill Turnbull).

The Balding Team (Clare Balding, Clive Anderson, and Sir Simon Jenkins) take on the Scrabblers (Alice Arnold, Konnie Huq, and John Finnemore).

The Scribblers (Alice Arnold, Charlie Brooker, and Ed Smith) take on the Terriers (Clare Balding, Val McDermid, and Joshua Levine).

The Noggins (Robert Peston, Patrick Marber, and Sophie Grigson), face the Curiosities (Kevin Eldon, Professor Steve Jones, and Kate Mosse).

The Waterbabies (Reeta Chakrabarti, Tom Holland, and captain Patrick Marber) compete against the Tillers (Katie Derham, Steve Pemberton, and their captain, Professor Steve Jones).

The Music Monkeys, featuring captain David Baddiel with Clemency Burton-Hill and Philip Hensher, square up to the Chess Pieces, a team lead by Hugh Dennis and featuring Bonnie Greer and AN Wilson.

The Royal III - David Baddiel, Dr John Cooper Clarke, and Philippa Gregory - square up to the BBC - Hugh Dennis, Julian Lloyd Webber, and Lynne Truss.

Series 9 champions the Europhiles take on Series 11 winners the String Section.

The Footballers and Korfballers return for a very special one-off sports special.

The Lasletts and Meeples return for a special family edition.

The QI Elves and Inquisitors compete in a special edition of the quiz.

Two former teams with a connection to travel return.

Two former teams with a connection to drinks return for a happy hour special.

Two former teams with a connection to education return for a special.

Series 12 champions the Verbivores take on series 13 champions the Escapologists.

Two favourite family teams from previous series return for a family-themed Christmas special.

Two favourite teams from previous series – one from the north and one from the south - return for a very special episode with a geographical flavour.

Six favourite contestants from previous series return for a one-off special themed around doctors.

Two favourite teams from previous series return for a very special musical episode.

Two favourite teams from previous series return for an evening of cheese, wine, and Christmas quizzing.

Two teams from previous series – the Birdwatchers and the Beekeepers - return for a special episode.

The Nordiphiles and Apres Skiers return for a very special and chilly episode.

Series 15's champions, the 007s, take on Series 16's champions, the Puzzle Hunters.

It's Christmas (special) time! Mistletoe and wine, boughs of holly, jolly teams from yesteryear oozing Christmas spirit and eager to tuck into some delicious questions.

It’s a mystery-themed special, and two teams emerge from the mists of time to attempt to solve a series of mysterious puzzles.

In this love-themed special, two teams from previous series have been lured out of retirement by the prospect of some lovely questions.

Two all-conquering teams from previous series battle for the title of champion of champions – the Dicers (Series 14) and the Data Wizards (Series 17).

A special festive edition, where two family teams return for a yuletide battle of wits.

Two fashionable teams from yesteryear return to strut their stuff.

There’s been a mix-up, but never mind: two ‘sporting’ teams from previous series have returned to fight it out.

Previous contestants return – professional politicians, including a real, live Conservative MP (correct at time of recording), face a team of activists.

Two teams from previous series return for a battle royal, and the questions are as tricky as ever.

It’s Christmas, and two family teams return for Only Connect’s most Christmassy Christmas special yet.

Two teams from previous series, both taking their names from giants of literature, face fiendish, bookish questions.

Teams from the first series return to celebrate 60 years of BBC Two.

Anything and everything relating to the ‘special relationship’ is on the cards, as two British quizzers and their US captain take on a British captain and his two US teammates.

It’s the ‘single special’, celebrating singles, solos, and everything that comes in groups of one.

Two teams from previous series return, but there’s a twist to the format – nearly all the questions are audio only.

It’s everyone’s dream to be a champion, and it’s every champion’s dream to beat another champion. Now is their chance.

Charge your glasses, it’s the Only Connect Pub Quiz! The format has been tweaked, and the budget has been blown on several packs of pork scratchings.

It’s Christmas, and two families from series gone by have battled traffic jams and rail replacement bus services to come together and play an exasperating game.

The law is under the spotlight in this episode. As indeed is a judge’s wig, which turns out to be surprisingly itchy.

Ever wondered who would triumph if the winners of the third-place play-off from one series took on the winners of the play-off from another?