The peninsula's plural arrangement ended by decision rather than by drift, and the decisions are dated.
Granada surrendered in January 1492 on terms that guaranteed its Muslim population their religion. Those terms were abandoned within a decade: forced conversion followed, and the descendants of the converts, the Moriscos, were expelled from Spain between 1609 and 1614. The Jews of Castile and Aragon were ordered in March 1492 to accept baptism or leave within four months, and Portugal followed with a forced conversion in 1497.
The consequence for Judaism was the creation of the Sephardi diaspora, which reassembled in the Ottoman lands, in North Africa, in Italy and later in Amsterdam. It carried its own liturgy, its own legal tradition and, for centuries, its own Iberian speech, and the Ottoman cities where it settled became major centres of Jewish learning in their own right. The kabbalistic revival at Safed in the sixteenth century was largely the work of people whose families had come out of Iberia.
There was also a population that stayed and was baptised, and whose descendants were watched. Some kept Jewish or Muslim practice secretly across generations, some did not, and the Inquisition's records are the principal evidence for both, which is a difficult kind of evidence: it was produced by an institution with an interest in finding what it was looking for.