The Peace of Westphalia refers to the pair of treaties , the Treaty of OsnabrÃ 1\/4 ck and the Treaty of MÃ 1\/4 nster , signed on May 15 and October 24 of 1648 , which ended both the Thirty Years ' War and the Eighty Years ' War . The term Peace of Westphalia denotes a series of peace treaties signed between May and October of 1648 in OsnabrÃ 1\/4 ck and MÃ 1\/4 nster .