Most of the information about him comes from the writings on the life of Otto of Bamberg. He was most likely born around the turn of the twelfth century. In 1109 Wartislaw was defeated in the Battle of Nakło by Bolesław III Wrymouth, the Duke of Poland, to whom he became a vassal sometime between 1120 and 1123.
He agreed to pay tribute to Bolesław, as well as to Christianize Pomerania.
To that effect, he, along with Bolesław, backed Otto of Bamberg in his successful Conversion of Pomerania. By 1124 his residence was in (Kammin) Kamień Pomorski.
The last time he is mentioned explicitly in chronicles is by Saxo Grammaticus who describes a joint Polish-Danish expedition against Wartislaw around 1129/1130, which was directed at the islands of Wolin and Uznam. The Danish King Niels is supposed to have taken him prisoner but released later after the intervention of "King of the Obotrites" Canute Lavard.
The author of the chronicles of Otto does not give the name of Wartislaw"s wife, only that she was a Christian.
Otto also forced Wartislaw to send home his previous 24 wives and concubines before he could marry her. The Pomeranian chronicler Thomas Kantzow, writing almost four hundred years later, states that Wartislaw was married to a Heila from Saxony. She is supposed to have died in 1128 and the following year the Duke married Ida, the daughter of Niels of Denmark or of Canute Lavard (Kanztow changed his chronicles in subsequent editions in this respect).
However, the names and origins of both supposed wives have been questioned by later historians.
Edward Rymar argues that if Wartislaw had indeed been married to a German princess then sources such as the life of Otto would have surely mentioned that fact. Rymar hypothesizes instead that Wartislaw"s wife was probably from the Ruthenian Rurik dynasty.