This was the time when abbot Adelardus, reporting to the prince-bishop of Metz, built the abbey's main church and two additional churches in town: Our Lady ('') and Sint-Gangulfus. Under the abbot's direction, Sint-Truiden also received an earth wall surmounted by a wooden fence and fortified gates. A proper defensive stone wall, gates and towers, were built in 1129. The economy of this new oppidum city was based on the linen industry. In addition, it traded successfully with such foreign lands as England, Champagne, and Germany.
This was the time when abbot Adelardus, reporting to the prince-bishop of Metz, built the abbey's main church and two additional churches in town: Our Lady ('') and Sint-Gangulfus. Under the abbot's direction Sint-Truiden also received an earth wall surmounted by a wooden fence and fortified gates. A proper defensive stone wall, gates and towers were built in 1129. The economy of this new oppidum city was based on the linen industry In addition, it traded successfully with such foreign lands as England, Champagne, and Germany.