John van Sierck (or Zyrick) (died 1305) was a bishop

Bishop

A bishop is an ordained or consecrated member of the Christian clergy who is generally entrusted with a position of authority and oversight. Within the Catholic Church, Eastern Orthodox, Oriental Orthodox Churches, in the Assyrian Church of the East, in the Independent Catholic Churches, and in the...

 of Utrecht from 1291 to 1296.

John van Sierck was archdeacon

Archdeacon

An archdeacon is a senior clergy position in Anglicanism, Syrian Malabar Nasrani, Chaldean Catholic, and some other Christian denominations, above that of most clergy and below a bishop. In the High Middle Ages it was the most senior diocesan position below a bishop in the Roman Catholic Church...

 in Treis-Karden

Treis-Karden

Treis-Karden is an Ortsgemeinde – a municipality belonging to a Verbandsgemeinde, a kind of collective municipality – in the Cochem-Zell district in Rhineland-Palatinate, Germany. It is the seat of the like-named Verbandsgemeinde to which it also belongs...

 in the Archbishopric of Trier

Archbishopric of Trier

The Archbishopric of Trier was a Roman Catholic diocese in Germany, that existed from Carolingian times until the end of the Holy Roman Empire. Its suffragans were the dioceses of Metz, Toul and Verdun. Since the 9th century the Archbishops of Trier were simultaneously princes and since the 11th...

, and papal chaplain

Chaplain

Traditionally, a chaplain is a minister in a specialized setting such as a priest, pastor, rabbi, or imam or lay representative of a religion attached to a secular institution such as a hospital, prison, military unit, police department, university, or private chapel...

. In 1291 he was named bishop of Utrecht by Pope Nicholas IV

Nicholas IV

Nicholas IV can refer to:* Pope Nicholas IV * Patriarch Nicholas IV of Constantinople * Patriarch Nicholas IV of Alexandria...

, without prior election by the Utrecht Chapters

Chapter (religion)

Chapter designates certain corporate ecclesiastical bodies in the Roman Catholic, Anglican and Nordic Lutheran churches....

. Despite a strong rule, in which he reformed the ecclesiastic law, John was unable to remove Utrecht from the influence of Floris V, Count of Holland

Floris V, Count of Holland

Count Floris V of Holland and Zeeland , "der Keerlen God" , is one of the most important figures of the first, native dynasty of Holland . His life was documented in detail in the Rijmkroniek by Melis Stoke, his chronicler...

, a legacy of his predecessor John I of Nassau

John I, Bishop-Elect of Utrecht

John I of Nassau was Bishop-elect of Utrecht from 1267 to 1290.-Biography:...

.

John set up public notaries

Notary

A notary is a lawyer or person with legal training who is licensed by the state to perform acts in legal affairs, in particular witnessing signatures on documents...

 and was in constant conflict with the city of Utrecht

Utrecht (city)

Utrecht city and municipality is the capital and most populous city of the Dutch province of Utrecht. It is located in the eastern corner of the Randstad conurbation, and is the fourth largest city of the Netherlands with a population of 312,634 on 1 Jan 2011.Utrecht's ancient city centre features...

. In 1296 he was moved to the Bishopric of Toul, where he ruled as John I. It is unclear if the move was voluntary, or was done to make way for a successor that was more inclined to an alliance between the County of Flanders

County of Flanders

The County of Flanders was one of the territories constituting the Low Countries. The county existed from 862 to 1795. It was one of the original secular fiefs of France and for centuries was one of the most affluent regions in Europe....

 and England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.