Based on historical events, this fictional series dramatizes the story of Queen Elizabeth II and the political and personal events that shaped her reign. As the new decade begins, the royal family may be facing its greatest challenge yet—with the public openly questioning their role in 1990s Britain. On the 40th anniversary of her accession to the throne, Queen Elizabeth II (Imelda Staunton) reflects on a reign of nine prime ministers, the advent of mass television, and the decline of the British Empire. However, new challenges are on the horizon. The collapse of the Soviet Union and the transfer of sovereignty over Hong Kong mark a sea change in the international order that presents both obstacles and opportunities. Meanwhile, things are turbulent at home. Prince Charles (Dominic West) pressures his mother to divorce Diana (Elizabeth Debicki), a move that precipitates a constitutional crisis for the monarchy. The couple grows increasingly estranged and rumors swirl. With the media increasingly scrutinizing her, Diana decides to take the initiative and break family rules—by publishing a book that undermines public support for Charles and exposes discord within the Windsor family. Tensions rise further with the emergence of Mohammed Fayed (Salim Dow), who, driven by his lust for supreme power, uses his self-made wealth and power to try to gain a place in the royal family for himself and his son Dodi (Khalid Abdullah).