King Louis was the first French king to establish a port on the Mediterranean, surrounded as the area was in 1240 by other powers. He established Aigues Mortes, built canals to Montpellier and elsewhere, and the launched Crusades from it in 1248 and 1270. The water king? He was a negotiator, letting pass France's claims to Barcelona and Roussilion, in exchange for Spain letting pass its claims to Provence and Languedoc. And other claims in the north of France were adjusted between France and Henry of England, see http://elvis.rowan.edu/~kilroy/JEK/08/25.html. A reformer, he is known as Saint Louis.
He also fought in two, failed, Crusades. The ships carrying Crusaders from Aigues Mortes show a galley arrangement of oars.
The waters have silted in by now, but collapsed structures restored, and embarkation city now celebrates -- like the days-long Festival of Saint Louis.
1. The King and Pope Gregory IX, through the eyes of the Crusader: Crusaders went off to occupy a distant Holy Land with assurances that their sins would be forgiven, and it is no sin to kill an evildoer, an unbeliever.