First mentioned in 805 as a small trading settlement on the frontier of the Slavic lands, it became important under Otto I (the Great), who founded there (c. 937) the Benedictine abbey of Saints Peter, Maurice, and Innocent. In 962 it became the seat of an archbishopric, the boundaries of which were fixed in 968, comprising the bishoprics of Havelberg, Brandenburg, Merseburg, Meissen, and Zeitz-Naumburg. The archbishopric played a major part in the German colonization of the Slavic lands east of the Elbe.

Although it was burned down in 1188, Magdeburg became a flourishing commercial centre in the 13th century and was a leading member of the Hanseatic League. In that century it also established an autonomous municipal administration, Magdeburger Recht (Magdeburg Law), that later was widely adopted throughout eastern Europe. Its citizens, in almost constant conflict with the archbishops, became nearly independent of them by the end of the 15th century. Magdeburg embraced the Reformation in 1524 and was thereafter governed by Protestant titular archbishops. During the Thirty Years' War it successfully resisted a siege by imperial forces under Albrecht von Wallenstein (Wallenstein, Albrecht Wenzel Eusebius von, Herzog von Friedland, Herzog von Mecklenburg, Fürst Von Sagen) in 1629 but was stormed in 1631 by Johann Tserclaes, Graf (count) von Tilly (Tilly, Johann Tserclaes, Graf von), who burned and sacked the city and butchered about 20,000 of the city's 30,000 inhabitants.

By the Peace of Westphalia (Westphalia, Peace of) (1648) the archbishopric became a secular duchy, passing to the electorate of Brandenburg on the death of the last administrator (1680). In 1806 the fortress of Magdeburg surrendered to Napoleon without fighting and was included in the kingdom of Westphalia until 1813. In 1815 the city became the capital of the newly constituted Prussian province of Saxony. The fortress was dismantled in 1912. Heavy bombing in 1945 destroyed much of the city, including the Renaissance city hall (1691).

Magdeburg is situated at a natural crossroads on the Elbe; it is at the junction of several major railway lines and arterial highways and is linked to the Rhine River by the Mittelland Canal and with Berlin and the lower Oder River by another system of canals. During the period of German partition, it was the most important inland port of East Germany; inland shipping remains significant. Although German reunification in 1990 brought steep declines in manufacturing activity (particularly machine building), the service sector of the economy expanded rapidly. Today Magdeburg is a centre of food processing, particularly sugar refining and flour milling, and of metalworking and heavy engineering. A chemical industry and textile milling are also significant.