The Principles of Masonic Law is a treatise on the constitutional laws, usages and landmarks of Freemasonry. The book is very informative and thorough, and it treats a wide range of topics in Masonic jurisprudence, providing a good insight to the overall governance of freemasonry. Freemasonry consists of fraternal organizations that trace their origins to the local fraternities of stonemasons that from the end of the fourteenth century regulated the qualifications of stonemasons and their interaction with authorities and clients. The basic, local organizational unit of Freemasonry is the Lodge. These private Lodges are usually supervised at the regional level by a Grand Lodge or Grand Orient. The degrees of Freemasonry retain the three grades of medieval craft guilds, those of Apprentice, Journeyman or Fellow Craft, and Master Mason.

Albert Gallatin Mackey (1807-1881) was an American medical doctor and author. He is best known for his books and articles about freemasonry, particularly the Masonic Landmarks. He wrote on a variety of subjects, but specialized in the study of several languages, the Middle Ages, and Freemasonry.