The Biathlon has its origins in Norwegian military patrols who were equipped with cross country skis and rifles. The first organized competetion to combine skiing and target shooting was held by these patrols in 1776, and continued in regular intervals through the 1800's. This lead to the founding of Trysil Rife and Ski Club, the first club of its kind, whose goal was to promote national defense locally. In 1902 Germany began holding military patrol races in the same style as the Norwegian competitions.
Military partrol races were then shown as a demonstrations port at the first Winter Olympic Games in Charmonix, France. Military patrol races would continue to be shown as demonstrations ports at the 1928, 1936 and 1948 Olympic Games. Finally in 1949 at the 44th session of the International Olympic Committee the Military Patrol would be accepted as an official event. However some changes were made, a proposal by Sweden the event was made an individual competition, opening it up to civilian competitors instead of just military personnel.
The name of the event was changed to simply Patrol Race to reflect the change. It isn't until the rules for the 1955 Winter Olympic Games are drawn up that the word Biathlon first appears. The Union International de Pentathlon Modern, the main managing body for many foot races, would go on to become the ruling body for Biathlon competition. The first Biathlon World Championships did not take place until the 1958 in Saalfelden, Austria and had only 25 athletes from 7 different countries competing in it.
Event thought the Biathlon was accepted as an Olympic event the first Olympic Biathlon competitions were not held until 960 when the event premiered in Squaw Valley, California. The original rules had competitors shooting rifles loaded with various large bore rounds at cardboard targets. The shooting distances were originally 250, 200, 150 and 100 meters. The race was original 20km with shooting sections laid out at equal intervals along the route. As technology and popularity progressed the cardboard targets would eventually be switched for glass targets, and then again for mechanical targets. The large bore rifles would be replaced with a standardized 22 caliber long round, with specific standards set for rife length, weight, and muzzle velocity. In modern competition the shooting distance has been adjusted down to 50 meters for all 4 shooting rounds, 2 of which are shot standing, and 2 of which are shot in the prone potions. It wasn't until the 1992 games the first Womens event was added to the Olympic roster.