Yet again Charles V
was faced with the problem of advancing Turks
so he called the Diet
of Regensburg. Only the Roman Catholic
Princes attended and they refused to give Charles
This meant Charles had to turn to the Lutherans. This lead to the Religious Truce of Nuremburg whereby the Lutherans promised to give assistance in return for Religious tolerance. In the event the Turk advance failed Charles V left the Empire to deal with other problems.