Complex sentence: According to Star Trek canon, the Klingon Kahless forged the first bat'leth around the Earth-equivalent of 625 A.D. Klingon mythology holds that he dropped a lock of his hair into the lava from inside a volcano known as the Kri'stak Volcano.
Split into simpler sentences: According to Star Trek canon, the history of the bat'leth is that the very first bat'leth was forged around the Earth-equivalent of 625 A.D. by the Klingon Kahless. He is stated to have dropped a lock of his hair into the lava from inside a volcano known as the Kri'stak Volcano.