A civil war in Spain from 1833 to 1839 - known as the First Carlist War was fought between supporters of the regent, Maria Christina, acting for Isabella II of Spain, and those of the late king's brother, Carlos de Borbón (or Carlos V) [i] Britain supported Maria Christina with money and military help in the form of the British Legion or Westminster Legion under General Sir George de Lacy Evans (1787 -1870) [ii]
References:
[i] http://en.wikipedia.org/wiki/First_Carlist_War
[ii] http://en.wikipedia.org/wiki/George_de_Lacy_Evans