CAST:

DID YOU KNOW?:

Although images of previous Doctors were seen in The Journal of Impossible Things from Series Three episode Human Nature, this is the first time a classic incarnation of the Time Lord has appeared in Doctor Who since its re-launch.

Peter Davison is the youngest Doctor to have been cast in the title role, being only 29 years old when he took over from Tom Baker at the end of the 1981 story Logopolis.

The striped trousers Peter Davison wears in this special episode are actually the ones especially altered for Sixth Doctor Colin Baker for his post-regeneration scenes in The Caves of Androzani.

As well as many New Series adventures, writer Steven Moffat previously scripted the charity episode The Curse of Fatal Death, screened in March 1999 as part of Red Nose Day.

Both Peter Davison and David Tennant have appeared in a Children In Need adventure. David joined Billie Piper for a special scene set straight after The Parting Of The Ways back in 2005, whilst Peter featured in the 3-D EastEnders crossover episode Dimensions In Time in 1993.

Peter's daughter, Georgia Moffett (Moffett is Peter's real surname), auditioned for the role of Rose Tyler back in 2005.

CLASSIC CONNECTIONS:

As revealed in The Caves Of Androzani, the Fifth Doctor wears a stick of celery on his lapel to warn him of gases in the Praxis range. He's allergic to them.

Both the Tenth and Fifth Doctors are good throwers. The Tenth threw a well aimed satsuma to finish off the Sycorax leader in The Christmas Invasion, whilst the Fifth was quite the cricketer (Davison actually bowled out an extra whilst filming a scene for Black Orchid!)

There are references to the TARDIS's Helmic Regulator (The Ark In Space and Smith and Jones), Ziton crystals (Vengeance On Varos), venting the thermo-buffer (Castrovalva) the Mara (Kinda and Snakedance) and Fifth Doctor companions Tegan and Nyssa.

Fact File compiled by Alistair Powell.