Willem IV of Horne (1303–1343) was Lord of Altena, Weert, Nederweert, Wessem, Heeze, Leende, and Cortessem.

He probably wanted to give it to Willem's younger brother Dirk, son of Gerard and the Count's sister Irmgard.

In 1327 Count William III of Holland then promised to maintain Squire Willem van Horne's possession of Altena as long as he did not get what he was entitled to.

[3] Shortly before his death, his father had finally asked the Count of Kleve to acknowledge his son Willem as Lord of Altena.

[6] Somewhat earlier, a coalition had been formed against Willem's liege lord John III, Duke of Brabant, members were his other liege lords the counts of Guelders, Loon and Gulik, as well the Bishop of Liège and Jan of Beaumont.

He did however create a feudal bond between his allodial villages Heeze and Leende, and the Brabant Duke in 1933.

[8] In turn the Brabant duke promised him the rich inheritance of his niece Beatrice of Louvain, lady of Gaasbeek and Herstal.

His second wife was Elizabeth, daughter and heiress of Dirk Loef III of Kleve, count of Hülchrath.

For the Land van Altena, its overlord the Count of Kleve did not want to recognize him straight away.

[12] Gerard I therefore sought the support of Nicolaas van Putten, a very influential man in the County of Holland.

[14] On 21 December 1315 a new treaty was made about the marriage of the then about 12 years old future Willem IV and Oda van Putten.