The calculated distance (air line) between Bonn and Ligny-en-Barrois is approximately 162 miles respectively 261 kilometers.
By car or train, the actual journey to Ligny-en-Barrois is certainly longer, as only the direct route (as the crow flies) between Bonn and Ligny-en-Barrois has been calculated here.
Air line (approximately)
261 kilometers
141 nautical miles