Margraviate of Landsberg
The Margraviate of Landsberg (German: Mark Landsberg) was a march of the Holy Roman Empire that existed from the 12th to the 14th century. It was named after Landsberg Castle in present-day Saxony-Anhalt. The territory was located between the rivers Saale and Elbe.
The margraviate was split off from the Saxon Eastern March (March of Lusatia) after the retirement of Margrave Conrad from the Wettin dynasty in 1156 and held by his son Dietrich I. He had the castle erected until 1174 and bore the title of a "Margrave of Landsberg".
In 1261 Margrave Henry III of Meissen again established Landsberg as a separate margraviate for his second son Dietrich. After Dietrich's son Frederick Tuta had died without issue in 1291, it was sold to the Ascanian margraves of Brandenburg. In 1327 Duke Magnus the Pious of Brunswick-Lüneburg inherited Landsberg by marrying Sophie, the sister of the last Ascanian margrave and also the niece of Emperor Louis IV. In 1347, Magnus sold it to Frederick II of Meissen, and in this way it fell back to the House of Wettin.