Answer
The Welsh national anthem is Hen Wlad Fy Nhadau, written by James James. It was first performed in 1856 and adopted as the national anthem in 1919. The tune of Hen Wlad Fy Nhadau is also used for the Breton anthem, Bro Gozh ma Zadoù. The Breton anthem was written by Théodore Botrel in 1893 and adopted as the national anthem in 1900.