Britain's King Charles III (R) arrives with Hamburg's Mayor Peter Tschentscher (L) and German President Frank-Walter Steinmeier to take part in a Green Energy Boat Trip in Hamburg, northern Germany on March 31, 2023. - Britain's Royal Couple is on a three-day tour in Germany for Charles' first state visit as king, with the trip billed as "an important European gesture" to maintain strong ties after Brexit. (Photo by Axel Heimken / AFP)