Socage is often described as "free and common socage" although the "free and common" qualification is now of a purely historical significance.
The concept of socage has evolved considerably since the Norman Conquest. In essence, it was a land-use system where a socman, sokeman or socager held his land from the King subject to a periodic duty to the King, such as military service, payment of money or provision of some service or goods.
Blackstone described it as follows:
"Socage, in its most general and extensive signification, seems to denote a tenure by any certain or determinate service. And in this sense it is by our ancient writers constantly put in opposition to chivalry, or knight-service, where the render was precarious and uncertain.”