He was a son of Bruno I, Count of Brunswick, and Gisela of Swabia.

[1] After the death of his father, Liudolf's mother remarried several times, her last marriage was to Conrad II, Holy Roman Emperor.

Therefore, Holy Roman Emperor Henry III was his younger half-brother.

[2] He controlled the Frisian counties Oostergo, Zuidergo and Westergo.

There is a theory that Liudolf took advantage of the reign of violence by the Counts of Holland in the part of Friesland between the Vlie and the Lauwers.