The Converso phenomena was not limited to the late 14th-16th centuries in Iberia. There were earlier occurrences of forced conversions and there were also cases of individuals voluntarily choosing to abandon Judaism. One of the more influential individuals to do so was Petrus Alfonsi. For a review of his life and works see the link below:

Petrus Alfonsi Vir Illustris et Ex Iudeo

Posted by Rabbi Juan Bejarano Gutierrez the director of the B’nei Anusim Center for Education. For a more complete review of Iberian Jewish history and the Crypto- Jewish Experience see The Rise of the Inquisition and Secret Jews: The Complex Identity of Crypto-Jews and Crypto-Judaism