Dominic West is reportedly close to a deal to join the cast of The Crown in the role of Prince Charles for its final two seasons.
The final major cast changes will take place after the next season - due for release on Netflix next month - with a whole host of new faces joining the show for its third act.
Imelda Staunton will replace Olivia Colman as The Queen, with Jonathan Pryce taking over as Prince Philip, Elizabeth Debicki portraying Princess Diana and Lesley Manville joining as Princess Margaret.
According to Variety, The Wire actor West is now in final discussions about starring opposite Debicki as Charles - The Queen's eldest child and first in line to the throne.
Seasons five and six will chart the events of the 1990s and the early 21st century, during which time Charles divorced Diana just before she was killed in a car crash, then went on to marry his long-term love interest Camilla Parker Bowles.
The Crown season four is released on Netflix worldwide on Sunday, November 15.