Netflix has unveiled the first The Crown Season 4 teaser trailer, offering our first look at the new season of the highly expensive and incredibly popular period drama series. This is the second season that finds Olivia Colman filling the lead role of Queen Elizabeth, but as it delves deeper into her reign, we’re introduced to Gillian Anderson as Margaret Thatcher and the teaser also heralds the arrival of Princess Diana. The season covers 1979 to 1990. Of course, it was just announced that Tenet star Elizabeth Debicki has been cast as Diana for the upcoming Season 5, so …