As early as the 1st millennium B.C., Assyrian sources mentioned an ancient Georgian state. Much later, when Christianity reached the Southern Caucasus, Assyrians and Georgians established much closer ties. In fact, the Assyrian monks, known as the 13 Assyrian Fathers, who arrived in the 6th century from Mesopotamia, played a great role in promoting Christianity in Georgia. The first Assyrian community appeared in Georgia thanks to King of Kartli and Kakheti Irakliy II, who secretly corresponded with Patriarch of the Assyrian Church of the East Mar Avraam with the aim of pooling forces against the Ottoman Empire. Their joint march against the common enemy failed; later several Assyrian families settled in Georgia in the Mukhrani district. The resettlement process continued when the Georgian kingdom-principalities became part of the Russian Empire. The Turkmanchai Peace Treaty of 1828 between Russia and Persia allowed Assyrians (who were Persian subjects) to move to Tbilisi, which offered better employment prospects. By the 1890s, there were about 5,000 Assyrians in Tbilisi. To avoid persecutions in the Ottoman Empire, Assyrians moved in large numbers to Georgia (and Armenia) during and after World War I. To help their compatriots, the Tbilisi Assyrians set up an Aid to Assyrian Refugees Committee and an Assyrian National Council.