The site's strategic value was obvious to Arnulf I, Count of Flanders, who ruled from 890 to 965. Two branches of the river Lys met here, creating a natural defensive position. Around the year 1000, the first fortifications appeared, initially in wood. Stone replaced timber, and the structure evolved into a motte-and-bailey castle, the standard military architecture of early medieval Europe. That fortress burned in 1176. The current castle dates from 1180, when the rebuilt Gravensteen emerged as a statement of Flemish power. A dedication stone from that year still marks the entrance, announcing the origins of what would serve as the counts' residence until 1353.

When the Counts of Flanders departed in 1353, the castle began its long decline. Courts met within its walls, and the dungeon held prisoners. From 1353 to 1491, the Gravensteen housed Ghent's mint, pressing coins in chambers where nobles once dined. Private buildings crept over and around the medieval remains, obscuring the original form. The Industrial Revolution transformed Ghent into a major textile center, and the castle's thick walls proved useful for a new purpose: a cotton mill took up residence within the fortress. Looms and spindles occupied spaces designed for armored knights. The conversion seemed logical at the time, putting old stones to profitable use.

The City of Ghent gradually acquired portions of the castle, recognizing that demolition would erase something irreplaceable. Beginning in 1893, Joseph De Waele led a restoration that lasted until 1907. His approach reflected Victorian sensibilities: a romanticized Gothic style that emphasized dramatic features and swept away the accumulated layers of later centuries. Photos from before the restoration show factory buildings still attached to the walls. During the work, these additions were demolished, revealing the medieval silhouette beneath. The result is not precisely what the 12th-century builders created, but it captures the spirit of a fortress built to intimidate.

The Gravensteen now serves as a museum, welcoming visitors to explore the great hall, the count's residence, the dungeons, and the ramparts with their views across Ghent's rooftops. The castle that once enforced aristocratic rule belongs to the city it once dominated. Inside, exhibits display arms and armor alongside the instruments of justice and punishment that were used when the building served as a court and prison. The transformation from seat of power to public monument mirrors Ghent's own journey from medieval trading powerhouse to modern Belgian city. On the streets below, cafes and shops fill the spaces where subjects once approached their lord's fortress with appropriate fear.