In the Anglo-Saxon period of English history, the majority of gilds (“frith gilds,” “crich ten gilds”) were religious, military, or social fraternities. In the Twelfth Century, a number of “secular gilds” began to arise, and it was these which later came to be called City Companies or (because certain of their members wore a prescribed costume) Livery Companies. The Exchequer Rolls of London show that by 1180 a number of these were legally organized; and because they could enforce laws, enact rules, levy fines and other penalties, etc., they had to have legal sanction for these governmental functions. This sanction was obtained in two ways: first, by having their rules and records approved at certain times by the Court of Aldermen, which was called Prescription; or, second, by receiving a Charter of Incorporation from the King.
If a company, society, fraternity, or gild undertook to perform gild functions without the required legal authorization, it was called an Adulterine (illegal) Gild; and after being tried and found guilty was heavily fined or otherwise punished, or was destroyed.
In 1181 no fewer than 18 such gilds were found in London, and each was heavily fined. The fact is important in Masonic history because it shows why Masons attached so much importance to their Charters, Old Charges, etc. To act in association or hold assemblies or enforce rules and regulations without legal authorization would have made of them an adulterine Gild. The Masons Company of London became a recognized body not later than 1220, and by prescription. In 1481 it received its “Enfranchisement,” or permission to wear Livery. In 1677 it received a Charter (a very expensive luxury) from Charles II. What Prescription, Enfranchisement, and Charter were to a City Company, the Old Charges must have been to Lodges; once such a Lodge set itself up as a permanent society its first thought would be to have a written sanction lest it be condemned as adulterine. By the same token, the new Grand Lodge of 1717 began as soon as possible to have a written legal instrument of its own, which took the form of the Book of Constitutions in 1723, and it compelled each new Lodge to have written warrant from it, and later, it began to issue Charters of its own to new Lodges.
A clandestine Lodge of the present time, which is a body without a regular Charter, is nothing other than the modern form of the ancient adulterine gild.