UdCa was founded in Ciudad Real by Emilio López Nieto, former secretary general of the PP in Ciudad Real, in December 2001 and formed, in part, by former members of the Regionalist Party of Castilla-La Mancha (PRCM).

UdCa defends the creation of a Castilian autonomous community, unifying the current 5 Castilian autonomies: Castilla y León, Castilla-La Mancha, Cantabria, Community of Madrid y La Rioja.

UdCa is seen as a regionalist party, although its president, Emilio Nieto, defends that Castile is a nation in Spain, so the party is also usually categorized as moderate nationalist organization.

[3] In the local elections of 2003 UdCa gained the mayorship in Puebla de Don Rodrigo and a total of 6 town councillors.

[4] In the local elections of 2023 the party gained 8 councillors in the Province of Valladolid, 3 in the Ciudad Real and 6 in Palencia.