故事发生在遥远的西汉时代，汉元帝当政期间，大汉的疆土早已在其曾祖父汉武帝的连年征伐之下拓展到西域纵深处。此时坐镇西域的大都护霍安（成龙 饰）并不以天朝上国的身份自居，他以友善平等的方式与西域各国交往，平等相待，更以独特的方式化解各民族之间的矛盾，取得了单靠武力所无法达到的和平盛景。谁知霍安遭人陷害，被刺配雁门关修城。恰在此时，他遭遇了从遥远的罗马帝国逃命至此的小王子及其护卫卢魁斯（约翰•库萨克 John Cusak 饰），最初的误解过后，霍安与卢魁斯两位英雄化敌为友。 　　但是危机之而来，企图夺得王位的罗马帝国大王子提比斯（阿德里安•布劳迪 Adrien Brody 饰）率领十万大军压境，东西方两大帝国即将发生前所未有的碰撞……When corrupt Roman leader Tiberius arrives with a giant army to claim the Silk Road, Huo An and his group of trained warriors teams up with an elite legion of defected Roman soldiers led by General Lucius to maintain the delicate balance of power in the region. To protect his country and his new friends, Huo An gathers the warriors of thirty-six ethnic nations together to fight Tiberius in an incredible epic battle.