Early medieval Cologne was part of
Austrasia within the
Frankish Empire. In 716,
Charles Martel commanded an army for the first time and suffered the only defeat of his life when
Chilperic II, King of
Neustria, invaded Austrasia and the city fell to him in the
Battle of Cologne. Charles fled to the
Eifel mountains, rallied supporters and took the city back that same year after defeating Chilperic in the
Battle of Amblève. Cologne had been the seat of a bishop since the Roman period; under
Charlemagne, in 795, bishop
Hildebold was promoted to
archbishop.
[5] In the 843
Treaty of Verdun Cologne fell into the dominion of
Lothair I's
Middle Francia – later called
Lotharingia (
Lower Lorraine).
In 953, the archbishops of Cologne first gained noteworthy secular power when bishop
Bruno was appointed as duke by his brother
Otto I,
King of Germany. In order to weaken the secular nobility, who threatened his power, Otto endowed Bruno and his archiepiscopal successors with the prerogatives of secular princes, thus establishing the
Electorate of Cologne, formed by the temporal possessions of the archbishopric and included in the end a strip of territory along the left Bank of the Rhine east of
Jülich, as well as the
Duchy of Westphalia on the other side of the Rhine, beyond
Berg and
Mark. By the end of the 12th century, the Archbishop of Cologne was one of the seven electors of the Holy Roman Emperor. Besides being prince elector, he was
Archchancellor of Italy as well, technically from 1238 and permanently from 1263 until 1803.
Following the
Battle of Worringen in 1288, Cologne gained its independence from the archbishops and became a
Free City. Archbishop
Sigfried II von Westerburg was forced to reside in
Bonn.
[11] The archbishop nevertheless preserved the right of capital punishment. Thus the municipal council (though in strict political opposition towards the archbishop) depended upon him in all matters concerning criminal justice. This included torture, the sentence for which was only allowed to be handed down by the episcopal judge known as the "Greve". This legal situation lasted until the French conquest of Cologne.[
citation needed]
Besides its economic and political significance Cologne also became an important centre of medieval pilgrimage, when Cologne's archbishop,
Rainald of Dassel, gave the relics of the
Three Wise Men to Cologne's cathedral in 1164 (after they, in fact, had been taken from
Milan). Besides the three magi Cologne preserves the relics of
Saint Ursula and
Albertus Magnus.
[12]
Cologne's location on the river Rhine placed it at the intersection of the major
trade routes between east and west as well as the main south–north Western Europe trade route, Northern Italy to Flanders. The intersection of these trade routes were the basis of Cologne's growth. By 1300 the city population was 50,000–55,000.
[13] Cologne was a member of the
Hanseatic League in 1475, when
Frederick III confirmed the city's imperial immediacy.
[5]