The 1920 Antwerp Olympics were held to honor those wounded in World War I and Belgian fighters. It was the first Olympics where athletes took an oath and the Olympic flag was raised with the five rings. National Olympic Committees selected participants. Track & field, boxing, cycling, football, gymnastics, swimming, modern pentathlon, tennis, and water polo were featured. Countries like the US, Sweden, UK, Finland, Belgium, Norway, Italy, France, and the Netherlands competed. The US won the most medals overall. Finnish athlete Paavo Nurmi was highly successful, winning 9 gold and 3 silver medals and becoming the most decorated Olympian at that time.