[4] The confusion about the dates is important, because count William V of Holland granted Altena to Willem's uncle Dirk Loef of Horne on 3 April 1357.

It is supposed that after Dirk Loef got the fief, his mother went to her father, taking the future Willem VI with her.

There are no indications that Albert or his predecessor cared about the legitimacy of the succession by Dirk Loef, and him styling himself as Lord of Horne and Altena.

[6] However, when Dirk made himself impossible with the count, and Otto, Lord of Arkel became very influential, Albert of Bavaria intervened.

In Holland Dirk Loef was forced to submit to a verdict which declared that he was only the guardian of Willem VI.

The latter without Loevestein Castle, but if Dirk Loef wanted to sell it, he first had to offer it to Willem VI for 3,500 Brabant mottoens.

Dirk Loef and his brother retained Herstal, Heeze, Leende, Montcornet, Bancigny, and Loevestein Castle.

Willem VI then probably went to Le Quesnoy in Hainault to receive the formal grant from regent Albert of Bavaria, count of Holland.

[8] During the First War of the Guelderian Succession (1371–1379) Willem VI fought on the side of John II, Count of Blois for a while.

This was caused by Bishop Jan van Arkel being in conflict with the other pretender, who was supported by William II, Duke of Jülich.

[9] After the marriage, and after Regent Albert's daughter was promised to the Jülich pretender, Willem VI was solidly on the side of Holland.

[10] In 1374, Willem VI helped Regent Albert to close a hole in the dike near Werkendam, without being obliged to do so.

On 20 December 1376 he gave the fief of Kortessem back to the Bishop of Liège, so it could be temporarily granted to Otto van Arkel.

However, on 8 May 1386, Albert ordered Dirk van Polanen to effect a cease fire between the Lords of Horne and Arkel.

However the details of the conclusion of the marriage contract between his daughter Oda and Jan van Ghemen make it likely that he was either ill or dementing at the time.