After Wilhelm's grandfather John I von Braunsberg died, King Ludwig IV (* 1282; † October 11, 1347) entrusted him with the Palatinate fiefs, especially the lordship of Wied, in 1227.
He first had to secure his grandfather's Braunsberg inheritance through a feud with Johann's sons-in-law Rorich of Renneberg and Burgrave Ludwig of Hammerstein from 1329 to 1331.
[1] On December 21, 1331, Wilhelm forced the Walpode Ludwig of Neuerburg to give his newly built Reichenstein Castle in the parish of Puderbach to him as a fief.
[3] On February 7, 1357, Wilhelm received town and market rights for Engers, Nordhofen and Almersbach from Emperor Charles IV in Maastricht.
In 1351, through his marriage to Johanna von Jülich, Wilhelm received as a dowry further rights to the County of Wied, the Office of Sinzig and the Lordship of Vernich.
They had the following children: After Johanna's death, he married Lysa (Elisabeth) of Arenfels († 1403), daughter of Gerlach III (* 1319; † around 1371), Lord of Isenburg-Arenfels from 1348 to 1371, in 1367.