Greece went into the war because its leader supported the Allied cause. Greece and Serbia had become independent, but many Greeks still lived in lands that were once Greek but were now in the Turkish Ottoman Empire. Having recently won the Balkan Wars, the Greeks especially wanted to control other land to the north that was under Bulgarian and Turkish rule, so they declared war. Turkey killed most of the Greek army as the Greeks tried to regain parts of Turkey. Another war started when the Greeks bombed a train. Turkey swept Greece back into their own territory. From then on the Greeks never again declared war, while Turkey had one of the biggest armies in the world. 