Nikolaus von Kues (Nicolaus Cusanus/Nicolaus de Cusa) lived in the pre-Renaissance period.
Nearly all his texts are published in critical reviews with the originals. The sources were collected in the Acta Cusana
(volume II is nearly finished).
He is known as a philosopher, as a theologian he really was just a semi-important prince of the church. What he did can be seen as a cross-section of the many-sided facets of the late medieval church.
Here in Germany, he is considered to be the first German humanist (or one of the first) and a modern thinkers of interreligious dialogue, who spoke out against the forcibly proselytizing of Jews and Muslims.