This drama follows the political rivalries and romance of Queen Elizabeth II's reign and the events that shaped the second half of the 20th century. The fourth season covers the time period between 1979 and 1990, is set during Margaret Thatcher's premiership, and introduces Lady Diana Spencer.Episode 01 – Gold StickAs Elizabeth welcomes Britain's first woman prime minister and Charles meets a young Diana Spencer, an IRA attack brings tragedy to the royal family.Episode 02 – The Balmoral TestMargaret Thatcher visits Balmoral but has trouble fitting in with the royal family, while Charles finds himself torn between his heart and family duty.Episode 03 – Fairy-taleAfter Charles proposes, Diana moves into Buckingham Palace and finds her life filled with princess training, loneliness, and Camilla Parker Bowles.Episode 04 – FavouritesWhile Margaret Thatcher struggles with the disappearance of her favourite child, Elizabeth re-examines her relationships with her four children.Episode 05 – Fag