Thursday, September 19th, 1963 - at Ealing Studios in West London actor Leslie Bates, standing in for Jeremy Young, casts a shadow over a sandy set... and over a Police Telephone Box. The cliffhanger to An Unearthly Child, the very first scene of Doctor Who committed to film, had been shot.

Principal filming wouldn't really get underway on Doctor Who's first serial until a few days later - the day after, Friday 20th, the main cast met for a photoshoot with the Radio Times:

At the time Doctor Who was a potential cover candidate for the esteemed magazine until Editors displayed a lack of confidence in the show, opting for a cover for Round the Horne instead (Who wouldn't get a Radio Times cover until 3 months later, for Marco Polo). Rehearsals for An Unearthly Child would start until the day after that, on Saturday 21st, but for now, a little piece of History in the making was already in the can.

[Radio Times]