Azerbaijan, officially the Republic of Azerbaijan, is a transcontinental country at the boundary of Eastern Europe and West Asia. It is a part of the South Caucasus region and is bounded by the Caspian Sea to the east, Russia's republic of Dagestan to the north, Georgia to the northwest, Armenia and Turkey to the west, and Iran to the south. Baku is the capital and largest city. The territory of what is now Azerbaijan was first ruled by Caucasian Albania and later various Persian empires.