'The five royal tribes of Wales' and 'The fifteen tribes of Gwynedd' refer to a class of genealogical lists which were compiled by Welsh bards in the mid-15th century. These lists were constructed on the premise that many of the leading Welsh families of their time could trace their descent to the 'five royal tribes of Wales' or the 'fifteen noble tribes of Gwynedd'. This is not to say that the lists are identical. The basic idea of five regal and fifteen common (i.e. noble) tribes was later used by the antiquarian and genealogist Philip Yorke as a model for his Royal Tribes of Wales (1799).