On 22 July 1225, he laid the foundation stone for the Dom Church, "Neubau iuxta formam templi Marienfeldensis aedificanda".
[3] Like his four younger brothers Engelbert, Philip, Bruno and Gottfried, Dietrich was destined for the church.
In 1218 he succeeded the Bishop of Münster, Otto I of Oldenburg, after his death during the Fifth Crusade in Syria.
Dietrich laid the foundation stone for the completion of the new construction of the Saint Paul cathedral in Műnster on 22 July 1225.
His role was abruptly cut short and continued by the chapter later that year, when his brother Frederick of Isenberg was involved in the death of their uncle Engelbert II of Berg, Archbishop of Cologne, on 27 November 1226, in Gevelsberg.