Excavations conducted in many of the local burial mounds have turned up Phrygian artifacts. After the Phyrgians, the city was occupied respectively by the Persians, Alexander the Great, and the Galatians. In 25 BC, the Emperor Augustus annexed the city and its Galatians kingdom. In the 4th century AD, there was a surge in Christianity in this region, where Saint Paul is said to have started the church. The 7th and 8th centuries saw the rise of Islam, and the city suffered many raids by the Persians and Arabs. The outer walls of the castle were built during this time. Between 871-893, Turks and Crusaders took turns occupying the city but in 1127 AD the city was brought under the domination of the Turks and given the name Enguriye. In 1402 as a result of the battle between Yildirim Beyazit and Tamerlane, the city was briefly in the hands of the Mongols. In 1414, however, it came under the rule of the Ottomans. During the war of independence in 1920, Ankara was chosen as a military base and in 1923 was declared the capital by Mustafa Kemal Ataturk, due to geographic, strategic and political considerations as well its role in the War of Independence. The foundations of the modern city were then laid, by bringing in city planners from Europe.