One of the major POD's of Greece is that there never was a Byzantine Empire. Instead in 330 CE, Greece split from East Rome, Constantinople never became the capital, and a new era of "re-Hellenization" began. So what we would know as the "Byzantine Empire" never truly existed. However, these true Greeks were much more diplomatic and when Venice came to take Greek possessions, its allies of the Holy Roman Empire and Russian city-states beat them back. Due to that & this empire being less into beautifying old ruins and cracking down on corruption, the Ottoman Empire did not go into Europe, and to this day The Second Empire of Greece still owns Cyprus, European Turkey, Albania, Macedonia and the Greek islands. However, in what would be Greece's Independence, the old ancient style culture was thrown off and the Greeks would brought into the 19th century. Soon, colonization began and Greece colonized what Libya, a failed conquest of Egypt, and going into Ethiopia. Today, Greece is more of a "Southern Switzerland" focusing more on commerce and trade, and putting down the "People's Liberation Front of Albania" which has been flooded with weapons and money from the Commune of Los Angeles and other Communist nations.
War with Rome
Greece has had a long history of city-building, architecture and trade. Its oldest city and capital is Athens, while its biggest and most populated is Byzantium.
Relations with other nations
Since the Ottomans never tried to invade Greece or any part of Europe for that matter due to a much stronger Hellenic Empire, and the parts of Greek controlled Turkey were either bought or conquered in the 1400s, there really is no bad blood between the two; on the contrary, they were able to become strong trading partners and even allies in the 1700s, forming a League between Greece, Turkey, Russia, Germany. So all in all, when war came about in World Wars I and II, Greece came to the aid of the Ottomans and Germans.
Things between these 2 nations has long been painted with hostility and war, culminating in the Greek capture of Libya and Somalia during World War II (see Libyan Succession Wars (PS-1)).
Sometime after WW-II, Greece got on quite friendly terms with foreign powers. Japan, a nation Greece fought with against the Allies and also a colonial empire shown not to always be looking out for other nations, began trading quite frequently with Greece. Soon, they signed a treaty of non-aggression. Next, the Confederate States of America and Scotland signed a treaty of non-aggression with Greece, as the SHE was always in conflict with England (a rival of Scotland) over colonies in North and East Africa, and the Confederate States were very promising trading partners. However, this made things somewhat cold between the SHE and the USA and Mexico.
Greece is of the few nations still in possession of colonies today. Some more liberal nations find this distasteful, while others (generally former colonial powers or even current ones, such as Japan) see nothing wrong with this and continue to trade with Greece to this day.