AStudio-bound, videotaped 'play' productions were the standard format for British Television from the early days to the 1980s. Acting, direction, and sets were technically done with a theatrical style. The reasoning was that such productions gave an intimate connection to the viewer, as if they are seeing a stage play or a Live TV-show. Dramas like I, CLAUDIUS, UPSTAIRS DOWNSTAIRS, ELIZABETH R and THE PALLISERS were referred to as Television Plays or 'Electronic Theater' (qtd. Alfred Shaughnessy).
AThe series is based on the novels I, Claudius and Claudius the God, written by Robert Graves in 1934 and 1935 respectively. Both novels and the series are written/played as an autobiography, suggesting Claudius wrote and concealed his account, believing an old prophecy that his work would be recovered 1900 years later, so future generations would learn of the murders, corruption and power struggle within the Roman Imperial family.It is indeed known that the real Claudius was a historian who wrote an autobiography spanning the same time period, that has since been lost. So the novels and series are not a direct adaptation of Claudius' work, like both novels andseries suggest.Instead, Graves based his story for a large part on the works of Roman historians Tacitus, Plutarch and Suetonius, and also from (transcripts of) speeches and letters made by the real Claudius (Claudius speech to the senate, reluctantly accepting the role of Emperor being the most notable). However, Graves also ignored several of the views in those historical works when they did not fit his narrative or character development (e.g. Claudius becoming a weak old man who is completely dominated by his family at the end of his life). Other elements that were mere conjecture in the historical literature were presented as facts in Graves' work (like Livia confessing several murders to Claudius).In short, the story has a firm base in historical facts, but has also been fictionalized to some degree.(Source: http://en.wikipedia.org/wiki/I_Claudius)