Marking the start of the annual harvest, Lammas takes place on the 1 August each year, and begins Lammastide, during which the grown wheat would be harvested. It is an old agricultural day linked to the Middle Ages, much like Plough Monday and Gang Day.
Lammas itself is a Christianisation of Lughnasadh, a Gaelic festival celebrating the god Lugh and the beginning of the harvest. The first cut of crops would be taken on Lammas Eve and baked into bread, which would be brought to church for the Loaf-Mass, or Lammas. There would be a procession following the bread as it was carried by the baker to the church, often with a raised standard or sign to alert the parishioners to join.
It was observed with bread of every new wheat, and in some places tenants are bound to bring new wheat to their lord, on, or before, the first of August. New wheat is called Lammas-Wheat.William Hone, The Every Day-Book : or the Guide to the Year
The Lammas bread had other uses, including being broken into four parts to be placed in the four corners of a barn to protect the harvested grain. The day would also be marked with festivities and games, such as building towers from soil and raising a flag upon it whilst simultaneously attempting to destroy neighbouring towers. This was a popular game amongst farmers in Scotland; however it was recorded throughout Britain at various times. Those defending towers could sound their tooting horn to summon locals to assist them, and often these neighbouring games would result in brawling and fighting, and even deaths.
The celebration of Lammas is still marked by some with the eating of the decorative loaf, but most other customs have gone from the annual calendar in Britain. A Lammas Fair still takes place in Exeter, with a procession marked by a white glove on a pole and decorated with garlands.