Casimir I (or Kasimir I) (after 1130 – fall of 1180) was duke of Pomerania since his uncle

Ratibor I Ratibor or Ratiboř may refer to: People * Ratibor (Polabian prince) (died 1043), a prince of the Obotrite confederacy from the Polabian tribe * Ratibor I, Duke of Pomerania (1124–1156), duke of the House of Pomerania (Griffins) * Ratibor II, Duk ...

's death in 1155/56. A son of

Wartislaw I Wartislaw I (''Warcisław I'') (around 1092 – August 9, 1135) was the first historical ruler of the Duchy of Pomerania and the founder of the Griffin dynasty. Most of the information about him comes from the writings on the life of Otto of ...

, he co-ruled Pomerania with his older brother Bogislaw I, receiving Pomerania-Demmin as his share just as Bogislaw received Pomerania-Stettin, and ruling the remainder in common. After the lost 1164

Battle of Verchen The Battle of Verchen (german: Schlacht bei Verchen) was a battle between Saxons and West Slavic Obotrites on 6 July 1164. The Obotrites were attacked by Saxons and Danes in 1160, resulting in the death of the Obotrite prince, Niklot, and th ...

, where Casimir and Bogislaw aided an Obodrite rebellion against the duke of

Saxony Saxony (german: Sachsen ; Upper Saxon German, Upper Saxon: ''Saggsn''; hsb, Sakska), officially the Free State of Saxony (german: Freistaat Sachsen, links=no ; Upper Saxon: ''Freischdaad Saggsn''; hsb, Swobodny stat Sakska, links=no), is a ...

Henry the Lion Henry the Lion (german: Heinrich der Löwe; 1129/1131 – 6 August 1195) was a member of the Welf dynasty who ruled as the duke of Saxony and Bavaria from 1142 and 1156, respectively, until 1180. Henry was one of the most powerful German p ...

, Casimir and Bogislaw joined Saxony receiving their respective part duchies as a fief from Henry the Lion. Casimir also received one third of the Danish ''terra'' Wolgast. When Saxony allied with the Danes to subdue the Rani kingdom of

Rügen Rügen (; la, Rugia, ) is Germany's largest island. It is located off the Pomeranian coast in the Baltic Sea and belongs to the state of Mecklenburg-Western Pomerania. The "gateway" to Rügen island is the Hanseatic city of Stralsund, where ...

in 1168, Casimir as well as Bogislaw aided Henry. Casimir also managed to take control in

Circipania Circipania (german: Circipanien, Zirzipanien) was a medieval territory in what is now northeastern Germany. The name derives from Latin ''circum'' (around) and ''Pane'' (the Peene River). The region was enclosed roughly by the upper Recknitz, Tr ...

, thereby expanding Pomerania to the West. Casimir participated in other campaigns launched by Henry the Lion, as an 1178/79/80 expedition into

Lusatia Lusatia (german: Lausitz, pl, Łużyce, hsb, Łužica, dsb, Łužyca, cs, Lužice, la, Lusatia, rarely also referred to as Sorbia) is a historical region in Central Europe, split between Germany and Poland. Lusatia stretches from the Bóbr ...

and Jüterbog. However, Casimir suffered heavy losses at the

battle at Julin Bridge The Battle at Julin Bridge was a naval and land conflict fought around 1170 between the kingdom of Denmark and the Pomeranians. It took place in modern-day Wolin, Poland. The Danish fleet was led by Valdemar I and Absalon and fought the army and ...

and later died in 1180 in a battle with Brandenburg margrave

Otto I Otto I (23 November 912 – 7 May 973), traditionally known as Otto the Great (german: Otto der Große, it, Ottone il Grande), was East Frankish king from 936 and Holy Roman Emperor from 962 until his death in 973. He was the oldest son of He ...

, having no children yet with his wife Pritolawa. Pomerania-Demmin was then governed by his brother Bogislaw and later by Bogislaw's second son Casimir II, his first son Bogislaw II receiving Pomerania-Stettin, so Pomerania would further be governed in a manner resembling the reign of Casimir I and Bogislaw I. Casimir founded monasteries in Broda (1170) and Belbuck (1177). He participated in founding the monastery Dargun (1172/74) and in 1176/80 granted privileges to the bishopric of Wollin that moved its seat to Cammin (now Kamień Pomorski) because of Danish expeditions.

See also