Although Serbian rulers at earlier times had at times relations with the Catholic West despite being Orthodox, as a counterbalance to Byzanitne power, and therefore tolerated the spread of Catholicism in their lands, under the reign of Stephan Dushan the Catholics were persecuted, as were also Orthodox bishops loyal to Constantinople. The Catholic rite was called "Latin heresy" and, angered in part by marriages of Serbian Orthodox with "half-believers" and the Catholic proselytization of Serbians, Dushan's code, the "Zakonik" contained harsh measures against them. However, the persecutions of local Catholics did not begin in 1349 when the Code was declared in Skopje, but much earlier, at least since the beginning of the 14th century. Under these circumstances the relations between local Catholic Albanians and the papal curia became very close, while the previously friendly relations between local Catholics and Serbians deteriorated significantly.