Who Were the Samaritans?

The gospel accounts in the New Testament speak periodically of a race of people called Samaritans. No effort is made by the gospel writers to cover up the historic enmity that had developed between this group and the Jewish people. John, the writer of the fourth gospel account, makes clear mention of this as he relates an encounter between Jesus and a Samaritan woman: "The Samaritan woman said to Him, "˜You are a Jew and I am a Samaritan woman. How can you ask me for a drink?' (For Jews do not associate with Samaritans.)" (John 4:9). So just who were the Samaritans, and why did the Jews hate them so, and vice versa?