During these years he had continued his studies in his leisure hours, and shortly after the Brazilian disaster he offered to write a history of the Portuguese in India, the Décadas da Ásia, which the king accepted.
この時期にも余暇を見つけては研究を続け、ブラジルでの災難の少し後にインドでのポルトガル人の歴史である『アジア史』(Décadas da Ásia) を書くことを提案し、王は承認した。