Jaromar Ier de Rügen (before 1141 - before August 1218) becomes, after the death of his/her brother Tezlaw de Rügen, prince of Rügen. He is the first duke of Rügen exerted the power under the durable suzerainty of Denmark.

According to the chronicler poméranien Thomas Kantzow (1505 - 1542), Jaromar is the son of the king of the Ranen (or Rugianie) Ratislaus de Rügen (1105 - 1140).

Saxo Grammaticus reports to us in 1264 that Ranen has to face several victorious attacks of Valdemar I {{er}} of Denmark and of Henri the Lion. Jaromar and its brother Tezlaw have to on several occasions recognize the Suzerain be of the invaders. Thus in 1162, the two brothers take part in the military forwarding of Valdemar against the area of Wolgast. In 1163, they are invited by Henri the Lion with the inauguration of the cathedral of Lübeck. In 1168, Valdemar Ier and the bishop Absalon definitively subject Rügen which becomes a Fief Danish. Tezlaw and Jaromir return a Hommage of Vassal ité to Valdemar and convert with the Christianisme. Tezlaw carries the title of prince de Rügen. As vassal, Tezlaw and Jaromar take part in Danish military forwardings against the Poméranie, in particular against Szczecin in 1170.

The name of Tezlaw is mentioned for the last time in the sources written in 1170. In 1181, a document gives the title of prince de Rügen to his Jaromar brother who succeeded to him.

In 1184, encouraged by the emperor Frederic Barberousse, Bogusław I {{er}} sets up a large fleet and lance an offensive against the island of Rügen. This attack is a complete failure. Its fleet is destroyed by Absalon and Jaromar. In reprisals, the Danes and the army of Jaromar launch several attacks against Poméranie, destroying the boroughs and the villages, progressing towards Kamień Pomorski. Not being able to prevent its attackers from advancing, Bogusław capitulates. In 1185, it pays a homage of vassalage to the king Knut VI of Denmark

After the death of Bogusław in 1187, at the request of Knut VI, Jaromar becomes in 1189 the guard of its two sons (Bogusław and Casimir).

Jaromar married Hildegarde of Denmark, the girl of the king Knut V of Denmark.

After the destruction of the castles of Arkona and Garz, it resided on Rugard. It made set up the first stone church, the Church Sainte-Marie de Bergen.