It was written in the aftermath of World War I and the Revolutions of 1917–1923, which saw the fall of the Hohenzollerns, Romanovs, Habsburgs and Ottomans. In contrast, Pope Pius XI pointed to a king "of whose kingdom there shall be no end". In 1925 the Pope asked the French Dominican priest Édouard Hugon, professor of philosophy and theology at the Pontifical University of Saint Thomas Aquinas, Angelicum, to work on Quas primas.Hugon O.P., Édourad. "Fuori della Chiesa non c'è salvezza", Accessed Feb. 6, 2013
