The League was founded by the city leaders of Bittburg and several other surrounding towns after the last margrave there died without an heir. Rumor has it that the margrave was poisoned. It is suspected that the margrave had been under the control of the merchant guilds for the last several years of his life. He was old & sickly. The death of the margrave was kept quiet. The merchant guilds in Bittburg took over the reins of the city. The merchant guild demonstrated good management of the city and since the territory was a small one things went unnoticed by the Empire. After several more towns and baronies joined the league it's power grew. Eventually through bribery or other means the Grand Duchy of Burgundy and many nobles in the Empire gave recognition to the league.
In the years since the league has prospered through their pro-merchant policies. However as the rich in the league grew richer the poor grew poorer and their freedoms dwindled. Now most of the common people in the league are serfs. The former city guard have been replaced by a small mercenary army. War is not in the leagues desires, not at the present. It interferes with profit, unless there are monetary reasons to start a war.