The Castle is a Radio 4 comedy set in the Middle Ages and referencing modern life - in the words of its own introduction, "a comedy set in the filth, stench and grime of the Middle Ages, with some nice music". The exact timeframe of the series is not fixed - one episode specifies it to be in the early 12th century, yet another references Joan Of Arc. It is written by Kim Fuller and - from series 2 - Paul Alexander with additional dialogue by Nick Doody, Matt Kirshen and Paul Dornan. It was first broadcast from Friday 7 September 2007, at 11.30am, and a second series began on Friday 2 January 2009 in the same time slot. Series 3 debuted on Wednesday 14 July 2010. Series 4 began its broadcast in 2012.
- Sir William De Warenne moves into the castle next door, and discovers the lovely Anne. Anne discovers the lovely Sam. Charlotte discovers that she is supposed to stay out of the way.
- An unexpected lion and the world's first satellite dish spell trouble for Anne and Sam Tree's ongoing romance.
- Sir William decides to woo Lady Anne with a swearing cook and a chocolate fountain.
- Sir John decides to open a theme castle and Sam Tree decides to save Unicorn Forest.
- The village pub acquires two new mysterious barmaids as Anne and Charlotte plot to ensnare Sam Tree. Sir William De Warenne gets in touch with his feminine side whilst Duncan gets in touch with his masculine one.
- Sir John tires of acting as the local magistrate, and hands the job to Sir William who, having realized that Sam stands between him and Anne, uses his position to condemn Sam to death. Unfortunately the scaffold is built using Thomas's latest invention - the flat pack.
- Houston We Have A Problemme - Sam leaves by rocket and Sir William fails a health and safety inspection of his torture chamber
- Nice To Gavotte You, To Gavotte You Nice - Ann seeks Sam's replacement, her father falls in love with the con artist Countess de Totty (Katy Brand) and Sir William enters Celebrity Strictly Come Gavotting
- Is This A Turnip That I See Before Me? - A theatrical troupe led by Will Shakeshaft (Lewis MacLeod) visits the town.
- Pool Party Of Doom - De Warenne invites his friend Earl of Essex and his daughter, hoping to flirt with the latter to make Ann jealous, whilst CSI arrives to investigate a murder victim from 15 years ago found by Time Team - who turns out to be Essex's twin brother
- Be Sure To Wear Some Flowers In Your Visor - Sir John Woodstock puts on a rock music festival, much to the annoyance of the Pope
- Something Old, Something New, Something Borrowed, Something Filled With Helium - Lord Clarkson arrives and tries to get his hands of Sir John's estate by marrying Ann so Peter Stringfellow can build a lap-dancing club there, and Merlin uses helium to give Charlotte a breast enhancement in an attempt to distract Clarkson
- The Dragon Of Mass Destruction - Sir William is interrogated by the Chilcott Enquiry, Sir John receives a letter from Lady Lumley of Purdey, and Henry falls in love with Lady Lindsay de Lohan.
- The Pilchards Of Doom - King Russell de Brand pays a visit, Sir John is challenged to a duel by Lady Lumley's husband, and Thomas attempts to discover the origins of the universe with the aid of Lord Hadron and his steed Collider.
- The Snowballs Of Hell - During an exceptionally cold winter (in August), Sir John permits the whole village population to move into the castle for the duration, but gang warfare soon breaks out. Meanwhile, Charlotte gets intimate with Merlin and Anne catches up with an old flame.
- The Vuvuzela Of Terror - Sir John struggles to convince His Majesty's Chancellor to pass his expense claims for moat-cleaning. To help justify the moat, Sir William stages a fake attack on the castle with some characters borrowed from Dad's Army.
- Four Wiseguys And A Funeral - Sir William sets out to write his autobiography, but is visited by gangsters who threaten to reveal his darkest secret.
- There's No Place Like Woodstock - Lord Andrew Lloyd Webber arrives in Woodstock, and stages a production of "The Wizard Of Oz" starring Lady Anne as Dorothy.
- Tender is the Knight - Sir John fills his castle with wounded soldiers and De Warenne fills his trousers with ice. Plus a new valet arrives hotfoot from somewhere called Downton Abbey.
- The Only Way is Ethics - Someone, or something, is hacking into peoples' private conversations and Master Henry could end up in jail. Meanwhile, Lady Anne has taken to nuzzling De Warenne's trusty War Horse.
- Highlights and Twilights - Two mysterious visitors, one deathly pale and one deathly orange. It's the love that dare not speak its name and the love that can speak its name but can't pronounce it properly.
- Boogie Knights - The wedding of the decade is almost ruined by 200 tents and an overexcited woodpecker, while Henry, Duncan and De Warenne gatecrash a rather special hen night.
- Give Me the Flaming Torch - The Olympics are coming to Woodstock, so what better time for Sir William to go on a go-slow and for Henry to hunt for dragons? Meanwhile, Sir John tries to get fit.
- A Term for the Worse - Anne's off to Cambridge, but Charlotte doesn't know the meaning of the word 'thick'. Literally. Is this the end of a beautiful friendship?