King Charles is the sovereign of the United Kingdom, head of state and host of state visits such as the October 2026 welcome for Sultan Haitham bin Tarik of Oman. At Windsor he greeted the Sultan with a handshake, rode with him in the Irish State Coach and presided over the state banquet. His daughter-in-law Catherine was not seen curtsying to him that day, most likely because she had already greeted him privately.
(Number 10 / Wikimedia Commons (CC BY 2.0))
Mentioned in: Kate Middleton’s Curtsy for the Sultan Showed a Princess Completely at Ease With Protocol