Spanish forces under Pedro Menéndez de Avilés capture the French Huguenot settlement of Fort Caroline, near present-day Jacksonville, Florida. The French, commanded by Rene Goulaine de Laudonniere, lost 135 men in the first instance of colonial warfare between European powers in America. Most of those killed were massacred on the order of Aviles, who allegedly had the slain hanged on trees beside the inscription "Not as Frenchmen, but as heretics." Laudonniere and some 40 other Huguenots escaped.
In 1564, the French Huguenots (Protestants) had settled on the Banks of May, a strategic point on the Florida coast. King Philip II of Spain was disturbed by this challenge to Spanish authority in the New World and sent Pedro Menéndez de Avilés to Florida to expel the French heretics and establish a Spanish colony there. In early September 1565, Aviles founded San Augustin on the Florida coast, which would later grow into Saint Augustine--the oldest city in North America. Two weeks later, on September 20, he attacked and destroyed the French settlement of Fort Caroline.
The decisive French defeat encouraged France to refocus its colonial efforts in America far to the north, in what is now Quebec and Nova Scotia in Canada.