Overall, Europeans formed only about a tenth of the royalist armies in Spanish America, and only about half of the expeditionary units once they were deployed in the Americas. Since each European soldier casualty was substituted by a Spanish American soldier, over time, there were more and more Spanish American soldiers in the expeditionary units. For example Pablo Morillo, commander in chief of the expeditionary force sent South America, reported that he only had 2,000 European soldiers under his command in 1820, in other words, only half of the soldiers of his expeditionary force were European. It is estimated that in the Battle of Maipú only a quarter of the royalist forces were European soldiers, in the Battle of Carabobo about a fifth, and in the Battle of Ayacucho less than 1% was European.