Because of the threat of the Ottomans to Europe, the Catholic powers were willing to co-operate with any and all factions which would have been potential enemies to the Turks. This did not just include the Orthodox powers of Southern Europe and the Levant such as Serbia and Cilicia — alliances were sought with "pagan heathens" such as the Mongols and even other Muslim powers such as the Safavids of Persia when they rose to power in the mid-16th century!