Nowadays, a defining feature of political life in the Basque Country is the system of autonomy that allows for a significant amount of decentralized decision-making authority. Currently, there are two different statues of autonomy for the Basque Country and Navarre. In the early 1930s, however, prior to the passing of a constitution for the Second Spanish Republic, a project for joint statute for the four provinces in Hegoalde was agreed on at a meeting of Basque mayors at the Gayarre Theater in Pamplona-Iruñea.
The draft Statute of Estella as it was known, drawn up by Eusko Ikaskuntza (the Society of Basque Studies), was approved on June 14, 1931 by a varied collective of mayors, with a Basque nationalist and traditionalist Carlist majority, from the four provinces of Hegoalde. One interesting feature of this draft proposal was to reserve the right for the projected Basque-Navarrese autonomous region to establish a separate and distinct relationship with the Vatican.
Ultimately, however, this draft proposal was never implemented and it was not until civil war broke out in 1936 that an autonomy statute was granted to the provinces of Araba, Bizkaia, and Gipuzkoa.
To read more about the political development of Hegoalde, check out Modern Basque History by Cameron Watson, available free to download here. And see Basque Political Systems, edited by Pedro Ibarra and Xabier Irujo, free to download here.