Greece has land borders with Albania, the Republic of Macedonia and Bulgaria to the north, and Turkey to the east. The Aegean Sea lies to the east of mainland Greece, the Ionian Sea to the west, and the Mediterranean Sea to the south. Greece has the twelfth longest coastline in the world at 13,676 km in length, featuring a vast number of islands , including Crete, the Dodecanese, the Cyclades, and the Ionian Islands among others. Eighty percent of Greece consists of mountains, of which Mount Olympus is the highest at 2,917 m.
Greece was the first area in Europe where advanced early civilizations emerged, beginning with the Cycladic civilization of the Aegean Sea, the Minoan civilization in Crete and then the Mycenaean civilization on the mainland. Later, city-states emerged across the Greek peninsula and spread to the shores of the Black Sea, South Italy and Asia Minor, reaching great levels of prosperity that resulted in an unprecedented cultural boom, that of classical Greece, expressed in architecture, drama, science and philosophy, and nurtured in Athens under a democratic environment.
Athens and Sparta led the way in repelling the Persian Empire in a series of battles. Both were later overshadowed by Thebes and eventually Macedonia, with the latter under the guidance of Alexander the Great uniting and leading the Greek world to victory over the Persians.
The Hellenistic period was brought only partially to a close two centuries later with the establishment of Roman rule over Greek lands in 146 BC. Many Greeks migrated to Alexandria, Antioch, Seleucia and the many other new Hellenistic cities in Asia and Africa founded in Alexander's wake.
The subsequent mixture of Roman and Hellenic cultures took form in the establishment of the Byzantine Empire in 330 AD around Constantinople. Byzantium remained a major cultural and military power for the next 1,123 years, until the Fall of Constantinople to the Ottoman Turks in 1453. On the eve of the Ottoman conquest, much of the Greek intelligentsia migrated to Italy and other parts of Europe not under Ottoman rule, playing a significant role in the Renaissance through the transmission of ancient Greek works to Western Europe. Nevertheless, the Ottoman millet system contributed to the cohesion of the Orthodox Greeks by segregating the various peoples within the empire based on religion, as the latter played an integral role in the formation of modern Greek identity.
The sortie of Messolonghi, during the Greek Revolution, by Theodoros Vryzakis.
After the Greek War of Independence, successfully waged against the Ottoman Empire from 1821 to 1829, the nascent Greek state was finally recognized under the London Protocol in 1830. In 1827, Ioannis Kapodistrias, from Corfu, was chosen as the first governor of the new Republic. However, following his assassination, the Great Powers installed a monarchy under Otto, of the Bavarian House of Wittelsbach. In 1843, an uprising forced the king to grant a constitution and a representative assembly.
Due to his unimpaired authoritarian rule, he was eventually dethroned in 1863 and replaced by Prince Vilhelm of Denmark, who took the name George I and brought with him the Ionian Islands as a coronation gift from Britain. In 1877, Charilaos Trikoupis, who is credited with significant improvement of the country's infrastructure, curbed the power of the monarchy to interfere in the assembly by issuing the rule of vote of confidence to any potential prime minister.