The term 'manor', which came in with the Conquest,[18] has a technical meaning in Domesday, referring to the system of taxation, and did not always coincide with the vill or village, though it commonly did so, except in the eastern portion of England. The village was the agrarian unit, the manor the fiscal unit; so that where the manor comprised more than one village, as was frequently the case, there would be more than one village organization for working the common fields.[19] The manor then was the 'constitutive cell' of English mediaeval society.[20] The structure is always the same; under the headship of the lord we find two layers of population, the villeins and the freeholders; and the territory is divided into demesne land and tributary land of two classes, viz. that of the villeins and that of the freeholders. The cultivation of the demesne (which usually means the land directly occupied and cultivated by the lord, though legally it has a wider meaning and includes the villein tenements), depends to a certain extent on the work supplied by the tenants of the tributary land. Rents are collected, labour superintended, administrative business transacted by a set of manorial officers. We may divide the tillers of the soil at the time of Domesday into five great classes[21] in order of dignity and freedom: 1. Liberi homines, or freemen. 2. Socmen. 3. Villeins. 4. Bordarii, cotarii, buri or coliberti. 5. Slaves. The two first of these classes were to be found in large numbers in Norfolk, Suffolk, Lincolnshire, Nottinghamshire, Leicestershire, and Northamptonshire. It is not easy to draw the line between them, but the chief distinction lay in the latter being more burdened with service and customary dues and more especially subject to the jurisdictional authority of the lord.[22] They were both free, but both rendered services to the lord for their land. Both the freemen and the slaves by 1086 were rapidly decreasing in number. The most numerous class[23] on the manors was the third, that of the villeins or non-free tenants, who held their land by payment of services to the lord. The position of the villein under the feudal system is most complicated. He both was and was not a freeman. He was absolutely at the disposal of the lord, who could sell him with his tenement, and he could not leave his land without his lord's permission. He laboured under many disabilities, such as the merchet or fine for marrying his daughter, and fines for selling horse or ox. On the other hand, he was free against every one but his lord, and even against the lord was protected from the forfeiture of his 'wainage' or instruments of labour and from injury to life and limb.[24]