information:classification, linguistic:voice_change
Final years (1555–1564)

Calvin's authority was practically uncontested during his final years, and he enjoyed an international reputation as a reformer distinct from Martin Luther. Initially, Luther and Calvin had mutual respect for each other. A doctrinal conflict had developed between Luther and Zurich reformer Huldrych Zwingli on the interpretation of the eucharist. Calvin's opinion on the issue forced Luther to place him in Zwingli's camp. Calvin actively participated in the polemics that were exchanged between the Lutheran and Reformed branches of the Reformation movement. At the same time, Calvin was dismayed by the lack of unity among the reformers. He took steps toward rapprochement with Bullinger by signing the Consensus Tigurinus, a concordat between the Zurich and Geneva churches. He reached out to England when Archbishop of Canterbury Thomas Cranmer called for an ecumenical synod of all the evangelical churches. Calvin praised the idea, but ultimately Cranmer was unable to bring it to fruition.

Calvin sheltered Marian exiles (those who fled the reign of Catholic Mary Tudor in England) in Geneva starting in 1555. Under the city's protection, they were able to form their own reformed church under John Knox and William Whittingham and eventually carried Calvin's ideas on doctrine and polity back to England and Scotland.

Within Geneva, Calvin's main concern was the creation of a collège, an institute for the education of children. A site for the school was selected on 25 March 1558 and it opened the following year on 5 June 1559. Although the school was a single institution, it was divided into two parts: a grammar school called the collège or schola privata and an advanced school called the académie or schola publica. Calvin tried to recruit two professors for the institute, Mathurin Cordier, his old friend and Latin scholar who was now based in Lausanne, and Emmanuel Tremellius, the former Regius professor of Hebrew in Cambridge. Neither was available, but he succeeded in obtaining Theodore Beza as rector. Within five years there were 1,200 students in the grammar school and 300 in the advanced school. The collège eventually became the Collège Calvin, one of the college preparatory schools of Geneva; the académie became the University of Geneva.