Doctor Who: 10 Things You Didn't Know About UNIT

10. The Brigadier And The Tenth Doctor Almost Teamed Up

The Sarah Jane Adventures featured a number of appearances by UNIT, given Sarah's connections to the organisation. Series 2 finale Enemy of the Bane brought Sir Alistair Gordon Lethbridge-Stewart out of retirement to help Sarah and the kids of Bannerman Road defeat Mrs Wormwood and a rogue Sontaran.

This was Nicholas Courtney's last appearance on TV as the Brigadier, driving off into the distance as Sarah waved him goodbye. The plan was to bring the Brig back in the following series for The Wedding of Sarah Jane Smith, where he would be paired up with David Tennant's Tenth Doctor.

But sadly, Courtney suffered a stroke in the months leading up to filming, meaning that he had to be written out.

The fact that the Brigadier never got to meet any of the modern Doctors onscreen is a disappointment for many fans, including Tennant. In an HBO Max interview, Tennant discussed how he was sad that he missed the chance to star alongside Courtney in The Sarah Jane Adventures, due to the actor's declining health.

Although not a patch on the real deal, the Tenth Doctor and the Brigadier did team up in comic-book form in the 2007 Doctor Who Magazine comic-strip, The Warkeeper's Crown.