Ferenc Dávid began to include Anti-Trinitarian ideas in his sermons, which infuriated the Calvinist bishop of Debrecen, Péter Melius Juhász. John Sigismund organized an open debate about the doctrine of Trinity, which was held in Gyulafehérvár in April 1566. After the debate John Sigismund granted funds to the Calvinist publishing house in Debrecen. He also sponsored the establishment of Protestant colleges in Kolozsvár, Marosvásárhely (present-day Târgu Mureș in Romania) and Nagyvárad. His letters to Petrus Ramus and other leading scholars of the Reformation show that he wanted to develop the royal college in Gyulafehérvár into an academy. An anthology of Italian poems, published in Venice in the 1560s, hailed John Sigismund as "patron of the Renaissance".