Quartus supra ([Twenty-]four) is an encyclical of Pope Pius IX, dated 6 January 1873, addressed to the Armenian Catholic Church.

[1] The encyclical discusses the then-ongoing schism within the Patriarchate of Cilicia, the election of bishops, and supremacy of the Holy See.

[1] In 1870, the First Vatican Council ruled that the Pope is preserved from error when speaking ex cathedra.

Followers of Jacob Pahtiarian seized local churches and forced the Patriarch Andon Bedros IX Hassoun into exile.

[1] Pope Pius IX addresses the encyclical to the "Patriarch of Cilicia, and the Archbishops, Bishops, Clergy and Laity, Our Beloved Children of the Armenian Rite Who are in Loving Communion with the Apostolic See".