Set in 19th Century England, France and Turkey, much of the filming of the series took place in Wales, as well as Oxford and south-west England.
Merthyr Mawr estate in Bridgend was used as the Holmes’ English estate, with filming also taking place in the market town of Monmouth and at Margam Park, near Port Talbot.
Bannau Brycheiniog, also known as the Brecon Beacons, provided the backdrop for a Chinese village in a flashback scene.
Hero Fiennes Tiffin plays the famous detective in his younger years, while Colin Firth plays Sir Bucephalus Hodge, the dean of Oxford University, where Holmes is a porter.
The eight-episode series is Ritchie’s second time bringing the detective to life on-screen, after directing the 2009 film Sherlock Holmes, starring Robert Downey Jr.