Spanish Regiment

I was just reading Davout's correspondence in June 1815. He writes to Lamarque in western France on 1 June 1815 that the general should "have the Spanish regiment which is at Tours brought to Saumur, it should soon be uniformed. If not then this can be done at Saumur". [Davout, Correspondance, p. 569].

Does anyone know what this Spanish regiment was and what became of it?