easants, in Spain, who harassed Napoleon's armies during the Peninsular War, in 1808-14.
The name is from the Spanish and means a little war.
The guerilla bands were led by bold bandits, who, inspired by hatred of the French and favored by the hilly character of the country, were successful on many occasions.
However, they were utterly lawless, and ready on the least suspicion of political treachery to turn their arms against the Spanish leaders.
One of the bands, led by the notorious General Mina, joined Wellington, and after having undergone a course of discipline, did good service as regular troops.
From Spain the name guerilla was brought to Central America, and thence to the United States.
Guerilla bands in Mexico and Texas were a source of great annoyance during the Mexican War. In the Civil War guerillas, or partisan rangers, as they were called, were commanded by officers duly commissioned by the Confederate President for such service.
By an act of the Confederate Congr