The Monumenta Germaniae Historica (frequently abbreviated MGH in bibliographies and lists of sources) is a comprehensive series of carefully edited and published primary sources, both chronicle and archival, for the study of German history (broadly conceived) from the end of the Roman Empire to 1500. Despite the name, the series covers important sources for the history of many countries besides Germany, since the Society for the Publication of Sources on Germanic Affairs of the Middle Ages has included documents from many other areas subjected to the influence of Germanic tribes or rulers (Britain, Czech lands, Poland, Austria, France, Low Countries, Italy, Spain, etc.). The editor from 1826 until 1874 was Georg Heinrich Pertz (1795–1876); in 1875 he was succeeded by Georg Waitz (1813-1886) .
The MGH was founded in Hanover as a private text publication society by the Prussian reformer Heinrich Friedrich Karl Freiherr vom Stein in 1819. The first volume appeared in 1826. The editor from 1826 until 1874 was Georg Heinrich Pertz, who was succeeded by Georg Waitz. Many eminent medievalists from Germany and, eventually, other countries, joined in the project of searching out and comparing manuscripts and producing scholarly editions. The motto chosen, Sanctus amor patriae dat animum ("Holy love for the fatherland gives the spirit") is explained as linking Romantic nationalism with professional scholarship.
In 1875, the MGH was established as a more formal institution with headquarters in Berlin. It was taken over by the state in 1935 and renamed the Reichsinstitut für ältere deutsche Geschichtskunde (National Institute for Older German History). This was abolished in 1945, at the end of World War II, but the institute was subsequently revived under its original name with the support of German institutions and the Austrian Academy of Sciences.