He opposed Duke Henry the Lion of Saxony and Bavaria, because of his bold power grab, and faithfully supported his liege lord, Archbishop Philip I of Cologne.
Around this time, he fought some devastating feuds against the Bishops of Münster and Osnabrück and the Count of Ravensburg.
A major feud broke out against the Counts of Ravensburg, who supported the Hohenstaufen in the struggle for the imperial crown.
Simon won this feud, and with it the fiefs Ravenburg had held from the Archbishops of Bremen and Cologne and from the Bishop of Paderborn.
Simon I was married to Oda (c. 1145 – 1224), the daughter of Count Eberhard I of Berg-Altena and Adelaide of Arnsberg.