The calculated distance (air line) between Frankfurt am Main and Ligny-en-Barrois is approximately 180 miles respectively 290 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 Frankfurt am Main and Ligny-en-Barrois has been calculated here.
Air line (approximately)
290 kilometers
157 nautical miles