A brief description of The Colloquy of Thorn, an attempt at uniting Roman Catholics and Protestants during the Protestant Reformation:
In 1645, King Vladislaus IV, Vasa of Poland, sought to unite all Christians, both Protestant and Roman Catholic. Representatives from the Roman Catholics, The Bohemian and Reformed, the Lutherans, and Dutch Arminians all gathered in the town of Thorn, in Germany. Each group was supposed to read their own concise confession, but only the Roman Catholics and Reformed were permitted to because arguments broke out and the gathering dissolved before a united statement could be reached.
 James T. Dennison, Jr., ed., introduction to “The Colloquy of Thorn (1645),” in 1600-1693, vol. 4 of Reformed Confessions of the 16th and 17th Centuries in English Translation (Grand Rapids: Reformation Heritage Books, 2012), 205-6.