1) chris columbus before he discovered america
2) Ying Zheng (so china wouldnt be a massive threat and/or unstabley (sp?) powerful)
3) Pope Urban II (so the crusades would never of happened and mllions of people would be spared. plus the teutonic order would not have been founded so germany would be divided by christianity and paganism thus not uniting under the kaizer so there would be no WW1, WW2 or cold war)