Caernarfon (the original Welsh spelling is now almost always used in preference to the anglicised forms, "Caernarvon" or "Carnarvon") is a royal town in north-west Wales. Caernarfon is the traditional county town of the traditional county of Caernarfonshire and was a county corporate in its own right.

The township was completely transformed by Edward I immediately after his conquest of Wales in 1282–83, for he built a large new stronghold around the motte and a walled borough adjacent to it, with a grid pattern of streets. The borough, to which he granted a charter in 1284, was made the capital of North Wales.

In 1911, David Lloyd George, then Member of Parliament for the borough, conceived the idea of holding the investiture of the new Prince of Wales at Caernarfon Castle, believing that this would help pacify nationalist opinion whilst arousing a more British patriotic feeling. The ceremony took place on July 13, with the royal family paying a rare visit to the principality, and the future King Edward VIII was duly invested. n July 1, 1969, the investiture ceremony was again held at Caernarfon Castle, the recipient on this occasion being Charles, Prince of Wales.