Maps of the Lands of the House of Orange

Principality of Orange
The original main title was taken from the Principality of Orange on the Rhone River outside Avignon and the papal lands of the Comtat Venaissin. The principality was 108 sq mi (280 km2). However, the prince was a sovereign monarch, which put him on the same plane as the kings and monarchs of Europe and the world. This is much the same situation as Monaco today.

Ancestral Lands
Initially, the family was known as “of Nassau” after their oldest possession the County of Nassau and their part of the subdivision of the lands, the Countship of Nassau-Dillenburg. This was divided and subdivided amongst the descendants of John the Elder. It generally comprised the northern part of the entire county of Nassau, north of the Lahn River. It was reunited in the 18th century under the line of Nassau-Dietz.

Subdivisions of Nassau
These subdivisions (baronies and lordships) of Nassau were split into semi-autonomous countships and pricipalities for the younger members of the House of Nassau. The title for these was Count of Nassau in xyz.

Other German Lands
Additionally, the House of Nassau acquired other lands in and around their ancestral estates:

Other Paternal Estates of the Royal House
Once the House of Nassau acceded to the royal throne, the Queens married with these representatives of other royal houses:

The Netherlands
Most of the estates of the family were in the Netherlands in the more populous provinces of northern Brabant, southern Holland, and Zealand, around the delta of the Rhine/Scheldt/Maas rivers, the trading center made by them, and its entrance to the sea. The land itself was secondary to the profit on the commerce that flowed through it and the political influence that accrued with them (see Western Netherlands Commercial Center which developed into Amsterdam Trading Center, which later developed into the Dutch Randstad.).

The family properties in the Netherlands centered around the Barony of Breda. The barony sat on the delta of the Rhine in northwestern Brabant. Before the revolt the main residence of the family outside the Nassau Palace in Brussels was the castle and fortress of Breda. It was as also relatively close to their important function of Viscount of Antwerp. This fortress withstood several sieges during the 80 years war if the Dutch Revolt, but is most famous for being captured in 1624 by the Spanish as immortalized by Velazquez.

The county of Vianden sat high above a tributary of the Moselle that flowed into the trade routes of the Rhine into western Germany and the Netherlands. In the 12th to 15th centuries the counts of Vianden were the mightiest lords of the area between the rivers Rhine, Mosel and Maas. Their territory was in modern Vianden canton, Luxemburg and Bitburg-Prüm, Germany.

William the Silent married as his first wife Anna van Egmont heiress of Maximiliaan van Egmond, Count of Buren. This also included the counties of Leerdam and Lingen. While these lands devolved to Anna's son Philip William, as he died without heirs, they devolved to the prince of Orange. The hier/eldest son of the prince of Orange was titled “Count of Buren”. It remains one of the subsidiary titles of the Dutch Monarch.

Northern Netherlands/later the Dutch Republic & the Kingdom of the Netherlands
These counties, baronies and lordships are in the official titulature of the monarch of the Netherlands:

These lordships are not in the official titulature of the monarch of the Netherlands, but are cited on the board in the picture.

The Southern Netherlands/later the Spanish & Austrian Netherlands, and the Kingdom of Belgium
While not as substantial as their interests in the northern Netherlands, the estates in the southern Netherlands were in the more populous provinces, in this case Brabant (most importantly Antwerp) around the river systems that ultimately flowed to the sea through the commercial entrepot of Antwerp. Again, the land itself was secondary to the profit on the commerce that flowed through it and the political influence that accrued with them (see Southern Netherlands Commercial Center which developed into Antwerp Trading Center, which later developed into the Belgian Flemish Diamond.).

These lordships are not mentioned in the titulature, but are shown on the board of Lordships:

Franche-Comté (Free County of Burgundy)
Franche-Comté was controlled by the King of Spain, so the princes of Orange lost control of the lands that they had inherited from the previous princes of Orange, the House of Chalon-Arlay, the Viscountship of Besançon and lordships of Chalons itself, Arlay, Nozeroy. By the time the King of France had conquered the county of Burgundy, the prince of Orange (William III) was at odds with the King, Louis XIV.