[{SlideShowNav}] !!!Caernarfon Castle (2) [{Image src='1830uk.jpg' width='800' alt='Caernarfon Castle (2)' class='image_left' height='542'}] [{SET customtitle='Caernarfon Castle (2)'}] \\ Inside Caernarfon Castle, Wales. The tradition of investing the heir to the throne of Britain with the title Prince of Wales was begun in 1301 when King Edward I invested Prince Edward with the title. Prince Charles was the last heir to be invested there in 1969.