Just 47 days into the job, Britain's King Charles III this week carried out his first significant constitutional responsibility as head of state, appointing Rishi Sunak as prime minister. Philip Kyle is an author who spent almost three years working for Charles's foundation, The Prince's Trust. He has just published the first biography of the new king in France. Kyle joined us for Perspective to discuss the challenges the 73-year-old monarch is likely to face, from keeping the royal family united to remaining political neutral as king.