On 6th April 1896, the Greek King, George I, officially opened the first summer Olympic games of the modern period at the Panathinaiko Stadium in Athens, Greece, with the words: "I declare the opening of the first international Olympic Games in Athens. Long live the Nation. Long live the Greek people." There then followed a performance of the Olympic Hymn, composed by Spyridon Samaras, with words by Kostis Palamas.
The event was the brainchild of the French educator and historian, Baron Pierre de Coubertin. Two years earlier he shared his hopes for the games:
May joy and good fellowship reign, and in this manner, may the Olympic Torch pursue its way through ages, increasing friendly understanding among nations, for the good of a humanity always more enthusiastic, more courageous and more pure.
Over the next nine days 241 athletes from fourteen nations participated in forty-three events. The nine sports competed in were athletics, cycling, fencing, gymnastics, shooting, swimming, tennis, weightlifting, and wrestling. Only men took part in the inaugural modern Olympics. Women athletes had to wait another four years until the second Olympiad in Paris to compete.
You can read more about the 1896 games on the official site of the Olympic Movement.
First international sports federation founded: 23rd July 1881
Tlatelolco Massacre: 2nd October 1968
Jim Hines won Olympic 100m final: 14th October 1968