The decree is dated 31 March 1492, three months after the surrender of Granada ended the last Muslim polity in the peninsula. Its stated reason is not theology but contamination: the presence of Jews, it argues, draws converted Christians back to the law of Moses, and lesser remedies, segregation and expulsion from particular districts, have been tried and have failed. The remedy chosen is removal from the whole of both crowns.
The terms are short. All Jews are to leave by the end of July. None may return on pain of death. No Christian may receive or shelter them after the deadline. They may sell their property and take movable goods, but not gold, silver, coined money or the other items the crown reserved, which meant that a house or a vineyard sold in a market of forced sellers realised very little and could not be carried out in a portable form.
Baptism was the alternative and it was open until the last day. Those who took it stayed, kept their property, and became subject to the Inquisition, which had been established in Castile in 1478 precisely to examine converts. The choice was therefore between exile with almost nothing and remaining under permanent suspicion. How many took each course is disputed; the older figures of two or three hundred thousand exiles are now generally regarded as too high, and modern estimates run considerably lower, but no count is secure.