La Salle, Robert Cavelier, Sieur de (1643-87), a great French explorer, was born at Rouen. He went to Canada in 1666, and some years later explored the country between Ohio and the lakes. Having obtained the support of the French Government, he descended the Mississippi, and at its mouth set up the arms of France on April 9th, 1682. He then returned to Europe, but in 1684 was given soldiers and four ships in order to attack the Spanish power in Mexico, the ostensible-object being to found a trade establishment at the mouth of the Mississippi. The expedition was unsuccessful; and, after two years' wandering about the borders of Texas, La Salle set out for Canada by way of the Mississippi. He seems, however, to have made himself unpopular by his harshness, and was assassinated by his followers near Trinity river.