Alexander the Great conquered Syria, Egypt, and Palenstine. He allowed lands under his control to continue observing their religions.
More than a century later Antiochus IV controlled the region. He began to oppress Jews and placed a Hellenistic priest in the temple. There was a massacre of Jews, he prohibited practice of Jewish religion.
Two groups led a revolt against assimilation of Hellenistic Jews. Oppression by Greek government revolution succeeded and the Temple was rededicated.
Tradition says that there was little oil that hadn't been spoiled by the Greeks. Oil was needed to burn the candles on the menorah and there was only enough to burn for one night. However the oil managed to burn for eight days.
The Menorah holds nine candles one for each night and a shammus at a different height. After blessings the first candle is lit and then each night candles are lit and then on the eighth night the ninth candle was lit.
It's a tradition to eat fried foods because of the significance of oil and it usually includes latkes.