Why is a self employed professionals are called as a "freelancer"?

The word freelance came out of the period between fourtneeth and sixteenth centuaries, when mercenary (primarily concerned with making money at the expense of ethics) knights (in recognition of merit) with no particular allegiance (loyalty or commitment to a superior or to a group or cause) would take their lances (a metal pipe supplying a jet of oxygen to a furnace or to make a very hot flame for cutting.) into battle for the prince or state that paid them the most money. they were referred to as freelancers in the nineteenth centuary and operated much like  the gunfighters in the american west. Now, a freelancer is anyone who work independently.