The noble House of Hornes was an important family, today extinct. Horne is a small village in Luxemburg.
Originally the Lord of Horne, was property of the Count of Looz. The First mentioned is Willaume, Sire of Hornes around 1100 and Arnould, Count of Looz and Lord of Hornes and Corswarem, maaried to Aleydis of Diest.
The Principality of Hornes was created on October 16, 1677, and was awarded to Count Eugene Maximillian (1631–1709) of Hornes. He was elevated to the rank of Prince, as Prince Eugene Maximilien of Hornes, second prince of the Empire. He was the son of Count Ambrosius of Hornes. This Royal House was started in the 9th century, by Count Conrad 1st. The principality was an enclave of Liège. This princely family was married into most of the royal families of Europe. This included the House of Bourbon. In the 14th century it was married into the Royal House of Savoy. This marriage in 1514 was between Jacob III of Horn and Claudina of Savoy. Claudina of Savoy, was the daughter of Philip II of Savoy. Jacob III later married Anna of Burgundy in 1530. They were also kin to the royal family of Płock. The principality gained greater power with these marriages. The principality was close to the Duchy of Cleves and Thorn, Netherlands. It held territory in what is now the modern Netherlands, Belgium, Germany, and France. These were the villages of Auchy-au-Bois, Lestrem in France ruled from 1722 to 1766 and Floringhem in France from 1774 to 1789. It became allied to France, and thus suffered during the French Revolution.