Gisilher, Gisiler, Giseler, or Giselmar (died 1004) was the second Archbishop of Magdeburg, succeeding Saint Adalbert

Adalbert of Magdeburg

Saint Adalbert of Magdeburg , sometimes known as the Apostle of the Slavs, was the first Archbishop of Magdeburg and a successful missionary to the Slavic peoples to the east of Germany...

, from 1004 until his death. In 981, the Diocese of Merseburg was united to that of Magdeburg. It was only separated on Gisilher's death.

From 971 to 981, Gisilher was the Bishop of the new see of Merseburg. When he was elevated to the archdiocese in that latter year, however, he suppressed the Merseburg bishopric on the basis that its creation (967 or 968) had not received the written consent of the Diocese of Halberstadt. The archbishop had the support of the Bishops of Zeitz and Meissen, who wished to aggrandise their own dioceses.

In 983, the Slavic tribes

Slavic peoples

The Slavic people are an Indo-European panethnicity living in Eastern Europe, Southeast Europe, North Asia and Central Asia. The term Slavic represents a broad ethno-linguistic group of people, who speak languages belonging to the Slavic language family and share, to varying degrees, certain...

 bordering eastern Saxony

Duchy of Saxony

The medieval Duchy of Saxony was a late Early Middle Ages "Carolingian stem duchy" covering the greater part of Northern Germany. It covered the area of the modern German states of Bremen, Hamburg, Lower Saxony, North Rhine-Westphalia, and Saxony-Anhalt and most of Schleswig-Holstein...

 rebelled. Havelberg

Havelberg

Havelberg is a town in the district of Stendal, in Saxony-Anhalt, Germany. It is situated on the Havel, and part of the town is built on an island in the centre of the river. The two parts were incorporated as a town in 1875...

 and Brandenburg

Brandenburg

Brandenburg is one of the sixteen federal-states of Germany. It lies in the east of the country and is one of the new federal states that were re-created in 1990 upon the reunification of the former West Germany and East Germany. The capital is Potsdam...

 were destroyed and the March of Zeitz

March of Zeitz

The March of Zeitz was a frontier county of the Holy Roman Empire, created through the division of the marca Geronis in 965, when the Emperor Otto I, on the death of Gero the Great. Its capital was Zeitz. Its first and only margrave was Wigger...

 devastated. In August, the margraves of Meissen, Lusatia, and the Nordmark

Northern March

The Northern March or North March was created out of the division of the vast Marca Geronis in 965. It initially comprised the northern third of the Marca and was part of the territorial organisation of areas conquered from the Wends...

 joined with the troops of the Bishop of Halberstadt under the leadership of Gisilher and defeated the Slavs at Belkesheim, near Stendal

Stendal

Stendal is a town in Saxony-Anhalt, Germany. It is the capital of Stendal District and unofficial capital of the Altmark. Its population in 2001 was 38,900. It is located some west of Berlin and around east of Hanover...

. Nevertheless, the Germans were once again limited to the land west of the Elbe

Elbe

The Elbe is one of the major rivers of Central Europe. It rises in the Krkonoše Mountains of the northwestern Czech Republic before traversing much of Bohemia , then Germany and flowing into the North Sea at Cuxhaven, 110 km northwest of Hamburg...

.

In March 984, Gisilher hosted Henry II, Duke of Bavaria

Henry II, Duke of Bavaria

Henry II , called the Wrangler or the Quarrelsome, in German Heinrich der Zänker, was the son of Henry I and Judith of Bavaria.- Biography :...

, in Magdeburg

Magdeburg

Magdeburg , is the largest city and the capital city of the Bundesland of Saxony-Anhalt, Germany. Magdeburg is situated on the Elbe River and was one of the most important medieval cities of Europe....

 on Palm Sunday

Palm Sunday

Palm Sunday is a Christian moveable feast that falls on the Sunday before Easter. The feast commemorates Jesus' triumphal entry into Jerusalem, an event mentioned in all four Canonical Gospels. ....

. He supported Henry for the regency of the young Emperor Otto III and perhaps even as king, for Henry received the commendation of the magnates at Magdeburg.

On his death in 1004, there followed a brief conflict between King Henry II

Henry II, Holy Roman Emperor

Henry II , also referred to as Saint Henry, Obl.S.B., was the fifth and last Holy Roman Emperor of the Ottonian dynasty, from his coronation in Rome in 1014 until his death a decade later. He was crowned King of the Germans in 1002 and King of Italy in 1004...

 and the cathedral canons before Tagino

Tagino, Archbishop of Magdeburg

Tagino was the third Archbishop of Magdeburg from 1004 until his death.Tagino was a chaplain of Henry II, Duke of Bavaria, when, in 995, the See of Regensburg became vacant...

 was installed as archbishop.

Sources

• Reuter, Timothy. Germany in the Early Middle Ages 800–1056. New York: Longman, 1991.
• Thompson, James Westfall
  James Westfall Thompson
  James Westfall Thompson was an American historian specializing in the history of medieval and early modern Europe, particularly of the Holy Roman Empire and France...
  
  . Feudal Germany, Volume II. New York: Frederick Ungar Publishing Co., 1928.