 News arrived in Montevideo in late 1822 that Prince Dom Pedro , son and heir of King João VI , had declared the independence of Brazil on 7 September and had been acclaimed emperor as Dom Pedro I on 12 October . Marques de Sousa was dispatched to Rio de Janeiro by the Baron of Laguna to pledge loyalty to the Emperor on behalf of the army in the south . The young alferes was an apt choice for the task ; he was well connected in the imperial capital ( his uncle , married to a paternal aunt , was Minister of War ) , cultured , and well educated . Marques de Sousa was a handsome man of average height with dark , curly hair and brown eyes . Fastidious about his appearance , he always took care to dress well , even during battles , and contemporaries made note of his trimmed and clean nails . He was also merry and gallant , with a " pleasant and well @-@ tuned voice in conversation , ample and resounding in command " . 
