Otto IV of Brandenburg

Otto IV, Margrave of Brandenburg-Stendal
Margrave Otto IV of Brandenburg, depicted in the Codex Manesse (c.  1300)
Born	c.  1238
Died	27 November 1308 or 1309
Noble family	House of Ascania
Spouse(s)	Heilwig of Holstein-Kiel Jutta of Henneberg
Father	John I, Margrave of Brandenburg
Mother	Sophie of Denmark

Otto IV, Margrave of Brandenburg-Stendal, nicknamed Otto with the arrow (c. 1238 – 27 November 1308 or 1309) was the Margrave of Brandenburg from the House of Ascania from 1266 until his death.

Otto was the son of John I and his first wife, Sophie of Denmark. His maternal grandparents were king Valdemar II of Denmark and his second wife, Berengaria of Portugal; his paternal grandparents were Albert II and Matilda of Lusatia.

After his father died in 1266, Otto IV ruled Brandenburg-Stendal jointly with his older brother John II and his younger brother Conrad I. Otto IV emerged as the most prominent of the three.

In 1269, Otto IV and his co-ruling brothers Conrad and John II accepted Duke Mestwin II of Pomerelia as their vassal (Treaty of Arnswalde). Later, the Duke of Pomerelia would resist Brandenburg sovereignty, leading to numerous feuds, the first of which erupted in 1278, when Mestwin militarily supported Bolesław the Pious against Brandenburg.

In 1277, Otto tried to have his younger brother Eric elected as Archbishop of Magdeburg. However, the Lords of Querfurt, who were Burgraves of Magdeburg, also fielded a candidate. As a compromise, Günther I of Schwalenberg was appointed. This led to a protracted dispute between Otto and the chapter of Magdeburg Cathedral. During the Battle of Fohse, Magdeburg managed to capture Otto and lock him in a cage. Otto's councillor Johann von Buch paid a ransom of 4000 pounds silver to have him released. The dispute continued during the reign of Günther's successor Bernard III of Wölpe.