The first version of the story of Chanukkah can be found in the First and Second Books of Maccabees; these two books are not part of the Torah, they belong to apocryphal literature. It is worth noting that Chanukkah is the only holiday that has no foundations in the Torah.
In these two books, neither the cruse of oil nor the miracle is mentioned. The festival of Chanukkah lasts eight days by analogy with the festival of Sukkot. This is because the Maccabees were unable to celebrate Sukkot as they were refugees in the mountains. Another reason is that consecrating a sanctuary takes seven days of purification, thus allowing consecration on the eighth day. It is also linked to the fact that the circumcision of baby boys is performed on the eighth day of life.
Chanukkah is also mentioned by Josephus (a Jewish historian from the first century CE). There, too, the miracle is not spoken of, but the festival is called "Light".
Chanukkah is not even mentioned in the Mishnah, whereas one would expect to find the rules for how candles are lit written down. Chanukkah is finally mentioned in the Gemara (Shabbat 21b) with the question "What is Chanukkah?". The answer given then speaks of the miracle of the oil.
Chanukkah was first celebrated as a remembrance of the victory of the Maccabees over the Greeks. Then it was celebrated as the re-consecration of the Temple (Chanukkah also means Consecration). Finally, it was celebrated for the miracle of the oil.
With the passing of time, the importance of the Maccabees' victory diminished, and to make sure that Chanukkah would not be forgotten, the emphasis was placed on its spiritual meaning and the symbol of the Menorah. During the Middle Ages, the reason for Chanukkah remained centred on the miracle of the oil, even though the story of the Maccabees' victory was well known. This story is in fact recounted in the Megillat Antiochus, insisting upon the martyrdom of the Jews (numerous Jews preferred to die rather than eat pork or bow down before an idol). Later on, and even today, the festival of Chanukkah has been influenced by the temporal proximity of the festival of Christmas, and it is customary to give money or gifts.
It should be noted that it was not the victory of Judah Maccabee and the re-consecration of the Temple that brought independence to the city of Jerusalem (Judea still remained under Syrian dominance). Beyond this fact, Chanukkah is meant to commemorate the victory of the weak over the strong.
(Source: summary from the book "The Jewish Festivals" by Michael Strassfeld)