sentences:  Before the Canal du Midi was constructed, the passage between the Atlantic Ocean and the Mediterranean Sea was along the Spanish Atlantic coast and through the Strait of Gibraltar.This route, more than 3,000 kilometers long, subjected sailors to the risks of attack and storms.Nero and Augustus in ancient times, then Charlemagne, Francis I of France, Charles IX of France, and Henry IV of France were all interested in constructing a canal which avoided the passage around Spain.