First episode of I, Claudius

The first episode of historical drama I, Claudius aired on 20 September 1976. The 12 part series was adapted by Jack Pullman from two novels by Robert Graves - I, Claudius and Claudius the God. The story of decadent imperial Roman life proved a critical and ratings success, and its mix of political intrigue, sex, and violence, helped turn Derek Jacobi into a star.

Jacobi's portrayal of the stammering Claudius was matched by an outstanding performance from Sian Phillips as Livia, his scheming grandmother. Both actors had to age though the series, and required hours in the makeup chair. The fine ensemble cast also featured memorable turns from George Baker, Brian Blessed, Christopher Biggins, Patrick Stewart and John Hurt (as Caligula).

Brian Blessed and Derek Jacobi look back on the series

I, Claudius proved that historical drama did not have to be staid. The popularity of the programme led to a repeat the following year, and inspired other historical dramas not to shy away from adult themes. I, Claudius won BAFTA Awards for Jacobi and Phillips, as well as one for Designer Tim Harvey. The title sequence featuring a snake slithering across a mosaic portrait of Claudius was parodied in the second series of comedy Blackadder.