The Liberal Union (Spanish: Unión Liberal) was a political party in Spain in the third quarter of the 19th century. It was founded by Leopoldo O'Donnell in 1858 with the intent of forging a compromise and taking a centrist position between the two forces that had hitherto dominated Spanish politics during the reign of Isabella II. On one side were the forces of conservative liberalism known as the doceañistas, arrayed around the Moderate Party. Among their leading figures were the queen mother Maria Christina of the Two Sicilies and General Ramón María Narváez. On the other were radical liberal exaltados or veinteañistas arrayed around the Progressive Party and the National Militia. Among their leading figures was General Baldomero Espartero. Both parties had fought on the same side in the