Causes In 1806-1807, Argentina's independence movement began when the British attacked Buenos Aires. This attack provoked two battles: the Reconquista and Defensa (see image below.)Around the same time, Napoleon Bonaparte invaded Spain and Portugal. He knocked Ferdinand VII out of power and caused a civil war in Argentina. At the time, there were two sets of government. Napoleon put his own brother, Joesph Bonaparte, on the throne. The other government was created by the patroitic juntas in Spain. They followed Ferdinand VII instead of Napoleon and were aided by the British. Also all over South America, there was a general sympathy for the regency, which was the office governed by a regent, or monarch. The claims made by the people were rejected due to an interregnum. This means a period when the normal government is suspended between successive reigns and, in this case, on the grounds of the ancient principles of spanish law, "The king's dominion's in America have the right to govern themselves pending the restoration of a lawful king."