More than 2000 years ago, the land of Judea (now Israel)was ruled by Antiochus, a tyrannical Syrian king. Antiochus forbade the Jews to observe the Sabbath or study their religious text, the Torah, and he erected a statue of Zeus in their sacred temple of Jerusalem (now the site of a mosque). In 167 B.C., the Jews -- driven to desperation -- rose up against Antiochus. It took three years of fighting, but eventually the Maccabees drove the Syrians out of Israel and reclaimed the temple in Jerusalem.
They cleansed and purified the temple, and rekindled the menorah, a candelabra that symbolized God's divine presence. Oddly enough, although it only held enough oil to burn for a single day, the menorah burned for eight. This was the miracle and thus the eight nights of Hannukah.