Why did the English eventually create a separation between church and state?

There was no creation of separation between a state and the church, freedom of religion was practiced willingly by the people.

Explanation:

Over the time past, there was nothing called the separation between the church of England and the state. there was a practice of freedom of religion for the people to to decide on which faith the believed in or what kind of worshiped they make in appreciation towards God.

Furthermore, not only that the Monarch is the head of the church, the Prime Minister plays an important role of his own, when choosing the Archbishop of Canterbury.

Traditionally there is no separation between state and the church of England, although there is freedom of religion. Not only is the Monarch head of the church, but the prime minister is still involved in choosing the Archbishop of Canterbury.