Montreuil was a thriving port before the river silted up in the 1300s (the sea is now about 25 km away).
Montreuil continues to do well as a working port, with no changes.
mnli hypothesis: Montreuil continues to do well as a working port, with no changes. premise: Montreuil was a thriving port before the river silted up in the 1300s (the sea is now about 25 km away).