The diocese Vladislaviensis , Polish: Wloclawek in Cujavia, near Plock, was first mentioned in a papal bull of 1148 by Eugene III.
The first bishop of Wloclawek was Warner, whose name appears in the 1148 bull , then Onoldius from Italy.
At some time the diocese was recorded as Vladislaviensis et Pomeraniae.
Various unsubstantiated claims as to various different years of establishment have been made by several Polish writers, starting in the 16th century.
For reference see Catholic Encyclopedia outside link: [