He supported Otto of the House of Welf as Holy Roman Emperor and was excommunicated in 1212 by Innocent III.

Dietrich's origins and family are not clear, although in the year 1166, he was appointed as pastor of the Saint Apostles church in Cologne.

After a decade of fighting and maneuvering, Otto had secured his own election, only to lose the throne in 1208 and regain it a year later.

In 1209, he secured his formal election and coronation as Holy Roman Emperor through the extension of promises to potential supporters in the German lands, and by agreeing with Pope Innocent III to curtail the imperial influence on the Italian peninsula.

The papal legate and the Archbishop of Mainz interceded, and later in 1212 replaced Dietrich with his opponent in the election of 1208, Engelbert von Berg.