1. The Three Doctors (1973)

The recent Royal Visit to the Doctor Who studios seems to have confirmed that John Hurt is indeed one of the Doctors and that the 50th Anniversary will be The Three Doctors Mark Two with the Hurt Doctor meeting the Tenth and Eleventh Doctors. So with that confirmation (Or it may be subtle misdirection. You never know with Steven Moffat at the helm), we continue the monthly countdown to Doctor Whos 50th Anniversary by looking back at that time-honoured Doctor Who tradition: the Multi-Doctor story...Well start with where it all began: 1973 and Doctor Whos tenth anniversary. The decision was made to unite the First, Second, and Third Doctors in a four-part story that saw them team up to take on Omega, a renegade Time Lord inhabiting a universe made of anti-matter. However, William Hartnells failing health led to a substantial rewrite that reduced the First Doctors role to a point where it was manageable for Hartnell, throwing more focus on the Second and Third Doctors. The relationship between the Second and Third Doctors turned out to be the focal point of the story with their clashing personalities leading to some great dialogue and situations, including the Second Doctors now famous line about not liking the way the Third Doctor redecorated the Tardis, as well as the general timey-wimey nature of the Doctors meeting each other being an excellent story element in itself. Despite the dodgy special effects (even for 70s Doctor Who), The Three Doctors is a story that has stood the test of time and is still a great watch forty years later. Its also the story that gave birth to celebrating Doctor Whos milestones in this way. A tradition that is still being carried on four decades later.