ALCAVALA, a duty charged in Spain and its colonies until the invasion of Napoleon (from Arab. al-quabalah, "tax," quabala, "to receive" ; c f . Fr. gabelle) . Originally imposed in 1 341 by Alphonso XI. to secure freedom from the Moors, it was an ad valorem tax of io%, increased afterwards to 14%, on the selling price of all commodities, whether raw or manufactured, and chargeable as often as they were sold or exchanged. This was a monstrous imposition which subjected every farmer, manufac turer, merchant and shopkeeper to the continual visits and ex amination of the tax-gatherers, whose number was necessarily very great.