Gernikako Arbola ("the Tree of Gernika" in Basque) is an oak tree that symbolizes traditional freedoms for the Biscayan people, and by extension for the Basque people as a whole. The Lords of Biscay (including kings of Castile and Carlist pretenders to the throne) swore to respect the Biscayan liberties under it, and the modern Lehendakari of the Basque Country swears his charge there.