The County of Champagne was a historical region in northeastern France, known for its strategic location and economic significance during the Middle Ages. It was established in the 10th century and became a prominent center for trade, particularly in wool and wine. The county played a crucial role in the development of the Champagne fairs, which were important commercial events that attracted merchants from across Europe. The county was ruled by a series of counts, with the most notable being the House of Champagne. The region's influence extended beyond trade, as it was also a cultural hub, contributing to the Gothic architecture seen in its cathedrals and towns. The Treaty of Troyes in 1420 marked a significant moment in its history, as it linked the county to the English crown during the Hundred Years' War.