Manuel de Mello's early Spanish verses are tainted with Gongorism, but his Portuguese sonnets and cartas on moral subjects are notable for their power, sincerity, and perfection of form. He strove successfully to emancipate himself from foreign faults of style, and by virtue of his native genius, and his knowledge of the traditional poetry of the people, and the best Quinhentista models, he became Portugal's leading lyric poet and prose writer of the 17th century.