Where did feudalism start?

Feudalism started in Western Europe after the collapse of the Western Roman Empire in the 5th century and lasted until the 16th century. Over this time period, feudalism waxed and waned as larger European empires formed and fell apart. Feudalism is an inherently decentralized form of power with weakened monarchs. A king or queen delegates lands and troops to vassals, and then those vassals do the same with their own vassals. But when bigger empires emerged, such as the Carolingian Empire (most of modern-day France and Germany) in the 8th and 9th centuries, feudalism decreased. The feudalism that we recognize--armored knights, dukes and counts, castles, manors, etc.--mostly emerged after the Carolingians collapsed in the 9th century.b