Medieval Society: The Three Orders
Our exposition of the three estates has been decidedly brief, however, it must again be stressed that medieval European society cannot really be understood without reference to this carefully graded hierarchy based on function and status. Indeed, prestige and status oftentimes became more important than wealth or land. Just the same, this tripartite division of society predominated European history right down to the 18th and 19th centuries when the French and Industrial Revolutions changed all social relationships for good. (Emphasis mine)
Or for evil.