Luther decided that only the Hebrew or Aramaic portions of the Old Testament should count (part of Daniel and a bit of Ezra are in Aramaic). Perhaps the reason for this was that he wanted to get rid of a verse in one of the books of Maccabees which was used by the Catholic Church to support the doctrine of purgatory and praying for the dead. The books of Maccabees are preserved only in Greek.
Thanks.
Luther was wrong.
Goes back a bit further than Luther doesn't it?