メルセン条約
Due to the deaths of Charles in 863 and Lothair II in 869, Burgundy and Lotharingia were again divided between East Francia, West Francia and the Kingdom of Italy by the 870 Treaty of Meerssen. The effects of the Treaty of Prüm came to a complete end, when in 951 King Otto I of Germany invaded and conquered Italy during a period of political unrest and married the former queen consort Adelaide. He attained the Iron Crown of Lombardy and was finally crowned King of Italy and Holy Roman Emperor in 962.