Greece achieved its independence from the Ottoman Empire in 1829. During the second half of the 19th century and the first half of the 20th century, it gradually added neighboring islands and territories most with Greekspeaking populations Following the defeat of Communist rebels in 1949, Greece joined NATO in 1952 A military dictatorship, which in 1967 suspended many political liberties and forced the king to flee the country, lasted seven years. Democratic elections in 1974 and a referendum created a parliamentary republic and abolished the monarchy Greece joined the European Community or EC in 1981 which became the EU in 1992. One of the great paradoxes of history is that the next hesitant advance of European civilization the development of the first city-states took place not on the fertile open central European plains but in a remote island to the south of the Aegean Sea which was completely lacking in metal resources. While the glittering mounted warriorprinces of central Europe dissipated their creative energy in warefare a highly cultured yet peaceful society built on trade and an agricultural surplus emerged on Crete. The history of Greece can be traced back to Stone Age hunters Later came early farmers and thecivilizations of the Minoan and Mycenaean kings This was followed by a period of wars and invasions, known as the Dark Ages In about 1100 BC, a people called the Dorians invaded from the north and spread down the west coast. In the period from 500-336 BC Greece was divided into small city states each of which consisted of a city and its surrounding countryside.