Ribault and his troops were stranded to the south. Menendez quickly moved to attack and massacred the French force on the shore of what became known as the Matanzas River, sparing only the Catholics among the French. With Fort Caroline captured and the French forces killed or driven away, Spain's claim to La Florida was legitimized by the doctrine of uti possidetis de facto, or "effective occupation", and Spanish Florida stretched from the Panuco River on the Gulf of Mexico up the Atlantic coast to Chesapeake Bay, leaving England and France to establish their own colonies elsewhere. While Spain's rivals did not seriously challenge its claim to the vast territory for decades, a French force attacked and destroyed Fort Mateo in 1568, and English pirates and privateers regularly raided St. Augustine over the next century. Fort Caroline Jean Ribault founded his colony at Port Royal in 1562, having previously come upon the St. Johns, which he called la Rivière de Mai (the River of May), because he saw it on the first of that month. Two years later, in 1564, Laudonnière landed at the Indian town of Seloy, the site of present-day St. Augustine, Florida, and named the river la Rivière des Dauphins (the River of Dolphins) after its plentiful dolphins; moving north, he established a settlement at Fort Caroline on the south side of the St. Johns, six miles from its mouth. Philip II of Spain, who regarded the possession of Florida as necessary for the safety of Spanish commerce, hearing that Ribault, who had returned to France, was organizing another expedition for the relief of his colony of Huguenots across the Atlantic, determined to assert his claim to the possession of Florida on the ground of prior discovery, and root out the French at all costs. Pedro Menéndez de Avilés had already been authorized to settle there, and his force was increased to enable him first to expel the French. Laudonnière, in the meantime, had been driven to desperation by famine, although surrounded by waters abounding with fish and shellfish, and had been partially relieved by the arrival of the ship of the English sea dog and slave trader Sir John Hawkins, who furnished him a vessel to return to France. They were awaiting fair winds to sail when Ribault appeared with his timely provisions and reinforcements. The plan of returning to France was then abandoned, and every