Together with the Foral Pass, the swearing of the Oath by the Lord appears as a fundamental item in order to guarantee the integrity of the Fuero. The first act of government by the Lord consisted of expressly and manifestly declaring to uphold the set of laws by which the lives of Biscayans were ruled.

I, Lord of Bizkaia, do swear that I shall well and truly observe and shall have observed all the freedoms, intimacies and privileges, uses, customs, that the Biscayans, whether from the open land or from the chartered towns, and from the Encartaciones and Duranguesado had had up to now and in the way that they have and desire them.

Lord of Bizkaia taking the Oath

The formula of the Oath can be seen in the Plenary Session Room of the Assembly Hall.

The lords of Bizkaia

The crisis of the Navarrese monarchy at the end of the 11^th Century allowed the Lord of Bizkaia to sever all subordination ties, consolidating himself in the territory, and to establish a hereditary Jurisdictional Lordship.

The oath-taking route

The acceptance, homage and swearing-in of the Lord has been, along with their legislative activity, one of the tasks of the General Assemblies since the 13^th and 14^th centuries.

The Lord "must come to Bizkaia in person and there he must confirm their privileges uses and customs and intimacies and freedoms and old laws and lands and favours they have " (1452 Fuero).

The Lord had to swear to uphold the Fueros prior to being accepted as the Lord of Bizkaia, and he had to do so in compliance with Title 1, law II of the Fuero: at the gates of the town of Bilbao, at the church of Santos Emeterio and Celedonio in Larrabetzu, in Gernika under the Oak Tree, and at the church of Santa Eufemia in Bermeo.