WATCH: 'The Crown' Season 4 trailer puts Princess Diana in the spotlight

Emma Corrin plays Princess Diana in the fourth season of 'The Crown'. Photo: Handout

Princess Diana (Emma Corrin) and Prince Charles (Josh O'Connor) take centre stage in The Crown Season Four trailer, which also offers first footage of Gillian Anderson in the role of Margaret Thatcher.

"Here is the stuff of which fairy tales are made – a prince and princess on their wedding day. But fairy tales usually end at this point, with the simple phrase, 'They lived happily ever after'," the trailer's narration says.

"As husband and wife live out their vows, loving and cherishing one another -- sharing life's splendors and miseries, achievements and setbacks - they will be transformed in the process. Our faith sees the wedding day not as the place of arrival, but the place where the adventure really begins."