23 December (releases)


 * 1967 - Episode one of The Enemy of the World was first broadcast on BBC1.
 * 1967 - Part five of the TV Comic story Flower Power was first published.
 * 1972 - Part four of the TV Action comic story Zeron Invasion was first published.
 * 1978 - Part one of The Power of Kroll was first broadcast on BBC1.
 * 1978 - Part two of the TV Comic story The Metal-Eaters was reprinted as a Fourth Doctor story.
 * 1989 - The Incredible Hulk Presents comic story Nineveh was first published.
 * 2009 - Part two of The Doctor on My Shoulder was first published online.
 * 2010 - The Companion Chronicles audio story Quinnis was first released by Big Finish Productions.
 * 2010 - Part six of Snowfall was first published online.
 * 2015 - The Fright Before Christmas was first published by Candy Jar Books.
 * 2015 - Black Dog was first released by Big Finish.