Construction of this structure, devised by King Henry IV and Sully in 1597, was part of a greater project to link the Mediterranean to the Atlantic and the Channel, by getting the River Loire and River Seine to converge, courtesy of a canal. But between the two bodies of water, a hill had to be got across at Rogny. Thus, engineer Hugues Cosnier created these six locks (ultimately seven) to level out the 24m difference. In 1642, the "Canal du Loyre en Seyne", today the Canal de Briare, was opened to navigation.