As Theresa May steps up into her role as Prime Minister and Hilary Clinton campaigns to take her seat in The White House, historian, broadcaster and writer Sarah Gristwood looks back to a group of lesser known but equally ambitious women striving for political power in 16th century Europe. From Isabella de Castille through to the coronation of Elizabeth I, Sarah’s new book Game of Queens examines the challenges faced by women in power – many of which still hold true today.