After the Norman Conquest of 1066, many written records of Lammas grazing regimes begin to appear throughout the British Isles. Often these are found in the records (Court Rolls) of the Manorial Courts Leet, which met to regulate the affairs of the Manors set up by landowners who took over England (as most of the southern part of Ynys Pryddein or Britannia had by then become known).
Under the Norman yoke, peasant farmers became tied to the land as villeins or as landless bordars, labourers who relied heavily on common pasturage for their subsistence. The poorest in society became serfs, who were little more than slaves and regarded as the personal property of the Lord of the Manor. Villeins and bordars often gradually sank into poverty and serfdom. The Norman Lords of the Manor claimed rights of ownership over the land, whereas in Saxon times ownership simply meant the right of use. The idea that the land itself could be owned by a mortal person was as foreign to the native villagers as the idea that the air or clouds could be owned; one could only establish traditional rights of use. The common hay-meadows were divided into strips over which the right to gather the hay crop could be bought and sold. The Lammas Lands maps of Leyton and Walthamstow Marshes show that even into the 20th century some hay-meadow strip owners still had Norman surnames (such as Bosanquet, pronounced “Bosney”), having bought or otherwise appropriated them from their former Anglo-Saxon owners. The people’s common rights of pasturage and so on, however, were almost always left intact.
Lammas Grazing rights were very important for ordinary country folk. In most places, rights of common were dependent on residence in a particular Parish, but the people of Walthamstow and Low Leyton “inter-commoned” - that is, anyone who lived in either Parish could graze their cattle on all of the marshlands between Lammas Day and Lady Day. Leyton and Walthamstow Marshes were collectively known as the Walthamstow Common Mead and there was a “slip” of land running across Leyton Marshes from the River Lea to Whipps Cross in Epping Forest which belonged to the Parish of Walthamstow.
Although the Half-Year system (1st August to 2nd February) was the most common, in many places the grazing season was from Lammas to some other date, often around the Spring Solstice, by which time the cattle would have had their fill of the nitrogen-rich fast-growing fresh new grass.
The practice of the Lammas grazing system is first recorded in Leyton and Walthamstow in the manorial records of Low Hall Manor and the Manor of Walthamstow Toni (or High Hall). The Manorial Courts supervised the Marshes and appointed the Marsh Hayward (an Old English title meaning Hedge or Boundary Warden, nothing to do with dried grass) at Whitsuntide each year right up to 1882, after which the Steward of the Manors appointed the Hayward out of court. In the 15th century, the dates when grazing was allowed in the water-meadows alongside the Lea were from Lammas Day (1st August) in late summer, until Lady Day (the start of the Christian year, 25th March) in spring.
After the 14th Century “Black Death” plague epidemic, the feudal system began to break down, and farmers were able to become free Copyholders, although they still did not own title (legal rights of ownership) over the land they farmed. Later, with new developments in agricultural practice, most importantly the introduction of scientific crop rotation and mixed farming, the great open fields of mediaeval tillage were enclosed for more intensive agriculture and the typical chess-board pattern of the 19th and early 20th century English rural landscape began to emerge. At the same time, the economic basis of society began to shift from the mediaeval hierachical structure of social obligations and custom to a nascent capitalist economic system based on production for profit.
With the change in the calendar in 1752, the parishes of Walthamstow and Leyton split on the issue of what dates grazing should commence and cease, and the Common Mead ceased to be intercommoned. A line of Black Poplar trees was planted along the Parish Boundary and extant maps of the Lammas Strips show either Walthamstow Marsh or Leyton Marsh but not the two together. However, it must be remembered that part of Leyton Marsh was within ‘The Slype’ or Walthamstow Slip (although not all of that area was subject to rights of common grazing).