During Medieval times, the region that is now Greece was once the centre of the massive Byzantine Empire, the western half of the even greater Roman Empire. After the Western Empire's fall from barbarians, the Eastern Empire continued to flourish for the next several centuries. It set Constantinople as it's capital, named after the great Roman Emperor, Constantine.
The Byzantine Empire eventually started to collapse and shrink, much like its predecessor. Around the time when the Ottoman Sultanate appeared, Byzantium was just shadow of its former self, clinging on to the Balkans and Trebizond, the only part of the empire left in Asia. By 1400, the Byzantine "Empire" owned just a handful of enclaves. The Ottomans had grown in size and power, and had established a strong foothold in Bulgaria after a successful war. The Byzantines were completely surrounded by their Turkish enemies and eventually, after many hard struggles, the magnificent city of Constantinople fell to Ottoman hands on the 29 May, 1453. This marked the end of the Medieval Age, aswell as the true Roman Empire (The Holy Roman Empire of Germany was neither "holy", "roman" or "empire"). The last few squabbling states of Greece that had gained independence from the Byzantines (Trebizond, Epirus, Athens, Morea, etc.) were quickly annexed by the Ottoman Empire.
In 1821, after almost 400 years of Turkish rule, the Greeks rebelled against their overlord. The Greek War of Independence lasted 11 years, and resulted in victory for the Greek people. And thus, the new state of Greece was born, the first nation to unite the Greek people under one banner successfully since Alexander the Great and Macedonia.
But the Ottomans don't take defeat very well, and the Sultan wants his land back. Greece is desperately trying to gather Great Power support, but it may be too late, for the armies of the Muslim terror are already in marching distance of the young state...
Greece sits comfortably over the Greek peninsula, its terrain consisting of many rivers and hills, making it a difficult land to attack. Greece also owns most of the Aegan Islands in the Mediterranean Sea, excluding Rhodes and Corfu.
The armed forces of Greece are underpowered compared to most nations in Europe, relying on Italian imports and stolen Ottoman equipment. The current standing number of troops in Greece numbers around 10,000 but many more can be conscripted in the event of war. The country does, however, have a fairly competent naval force, which is of course required to defend its many islands and archipelagoes. Crete houses a huge naval base, which even allows foreign navy ships to dock and repair, for a price. Due to Greece's awkward terrain, tanks and other armoured vehicles are a rare sight in the Hellenic Armed Forces. There is also no Air Force at this time, mainly due to lack of pilot training and costs.