Final answer:
Ferdinand and Isabella were the key influence in the conversion of Jews in Spain in 1492.
Step-by-step explanation:
The key influence in the conversion of Jews in Spain was Ferdinand and Isabella.
In 1492, Ferdinand and Isabella issued orders for all Jews and Muslims to convert to Christianity or leave Spain.
They saw the Reconquista of the Spanish peninsula as both a religious and military re-conquest, and the Catholic Church viewed it as a great victory for Christianity.