Around 1189, the City gained the right to have its own mayor, later being advanced to the degree and style of Lord Mayor of London. Over time, the Court of Aldermen sought increasing help from the City's commoners and this was eventually recognised with commoners being represented by the Court of Common Council, known by that name since at least as far back as 1376. The earliest records of the business habits of the City's chamberlains and common clerks, and the proceedings of the courts of Common Council and Aldermen, begin in 1275, and are recorded in fifty volumes known as the Letter-Books of the City of London.