Frederick II of Brandenburg , nicknamed "the Iron" and sometimes "Irontooth", was a Prince-elector of the Margraviate of Brandenburg from 1440 until his abdication in 1470, and was a member of the House of Hohenzollern.
Background
Frederick II was born in Tangermünde to Frederick I, Brandenburg"s first Hohenzollern ruler, and his wife Elizabeth, daughter of Frederick, Duke of Bavaria-Landshut, and Maddalena Visconti. The latter was a daughter of Bernabò Visconti and Beatrice della Scala.
Career
When Frederick I retired in 1437, he compensated his incapable eldest son John with the Principality of Bayreuth while Frederick II assumed the government of Brandenburg. Unlike his father, he turned away from imperial politics and concentrated on his efforts to pacify the nobility and towns of the electorate. Quarrels with the city of Berlin began in 1440 with his plans to build a new residence on the Cölln island of the Spree river.
In 1448 the Berliner Unwille (indignation) against the cession of the city"s territory for an electoral stronghold culminated in open revolt, when the citizens flooded the excavation of the future Stadtschloss.
Nevertheless, Frederick II prevailed, had the palace built and the city"s rights decisively curtailed. In 1454 and 1455, he concluded the Treaties of Cölln and Mewe and thereby re-gained the Neumark (New March) from the Teutonic Order state.