Leicester Square was given a royal makeover complete with palace style pillars, men marching in military uniform and even a corgi walked the red carpet.
It was all for the launch of Netflix's latest original series The Crown, which follows the life of Queen Elizabeth II.
British actress Claire Foy takes the role of Britain's longest reigning monarch, while former Doctor Who actor Matt Smith plays the Duke of Edinburgh.
It's reported The Crown cost £100 million, making it one of the most expensive TV shows of all time.