But his principal work was the "De republica ecclesiastica", of which the first part after revision by Anglican theologians was published under royal patronage in London (1617), in which he set forth with a great display of erudition his theory of the church. In the main it is an elaborate treatise on the historic organization of the church, its principal note being its insistence on the divine prerogatives of the Catholic episcopate as against the encroachments of the papal monarchy. In 1619 Dominis published in London from a manuscript Paolo Sarpi's "Historia del Concilio Tridentino". This history of the Council of Trent appeared in Italian, with an anti-Roman title page and letter dedicatory to James I. The manuscript had been obtained from Sarpi for George Abbot by his agent Nathaniel Brent.