Georgians arose from Colchian and Iberian civilizations of classical antiquity; Colchis was interconnected with the Hellenic world, whereas Iberia was influenced by the Achaemenid Empire until Alexander the Great annihilated it. In the 4th century, the Georgians became one of the first to embrace Christianity and now the majority of Georgians are Orthodox Christians, with most following their national autocephalous Georgian Orthodox Church, although there are small Georgian Catholic and Muslim communities as well as a significant number of irreligious Georgians. Located in the Caucasus, on the continental crossroads of Europe and Asia, the High Middle Ages saw Georgian people form a unified Kingdom of Georgia in 1008 AD, the pan-Caucasian empire, later inaugurating the Georgian Golden Age, a height of political and cultural power of the nation. This lasted until the kingdom was weakened and later disintegrated as the result of the 13th–15th-century invasions of the Mongols and Timur, the Black Death, the Fall of Constantinople, as well as internal divisions following the death of George V the Brilliant in 1346, the last of the great kings of Georgia.