Tiedemann Giese

Tiedemann Giese (1 June 1480 – 23 October 1550), was a member of the patrician Giese family of Danzig (Gdańsk, Poland). The Gieses originated from Unna in Westphalia. His father was Albrecht Giese and his brother, the Hanseatic League merchant Georg Giese. Another relative was Albrecht Giese. Tiedemann became Bishop of Culm (Chełmno) first canon, later Prince-Bishop of Ermland (Warmia).

Giese was born in Danzig. At age 24, he (and Mauritius Ferber) became a priest at the Catholic Church of St. Peter and St. Paul. Giese was supported by Chancellor Lucas David.

Bishop Giese was a close friend of the later famous astronomer and proponent of heliocentrism Nicolaus Copernicus. In 1516, he was the co-author, together with Copernicus, of a letter to the Polish King Sigismund I the Old asking for the King's protection of Prussia against the Teutonic Knights, and generally supported the interests of the Polish Crown against that of the Teutonic Order. He also worked on updating the Kulm law while a canon at Ermland. On 1 July 1536 he was designated by King of Poland, Sigismund I, who considered him a very valuable diplomat, as Bishop of Culm, which was later confirmed by the Pope. After Mauritius Ferber's death Giese became prince-bishop.

The Giese and the Copernicus family were related. Copernicus willed his writings to Giese and left his library to the church administration of the Prince-Bishopric of Ermland (Warmia).

He carried out active correspondence with Erasmus of Rotterdam and Philipp Melanchthon. Among his known publications is Centum et decem assertiones, quas auctor earum Flosculos appellavit de homine interiore et exteriore, a polemic with the proponent of Luther, Johann Briesmann. Most of his other works have been lost (including a work on Aristotle and one called De Regno Christi).

Bischop Giese died in Heilsberg (Lidzbark) and was laid to rest next to Copernicus at the Frauenburg (Frombork) cathedral.