The actual population of Scotland had thus consisted of three races—the two Celtic peoples of the Gael and the Brython or Britons, and the Teutonic people of the Angles. To these races had been added by King David the First and his successors the Norman barons, who were overlords of a great part of the territory of the kingdom, while a Norwegian population may to some extent have still lingered in the Western Isles. In endeavouring to ascertain the early social organisation of these three races, besides the few hints which historical documents afford, we have the advantage of an ancient code of laws of each race. For the Angles we have the Anglo-Saxon laws, and for the Britons the early laws and institutions of Wales, both published by the Record Commission.[155] For the Gael we have the ancient laws of Ireland, commonly called the Brehon Laws, now in course of publication;[156] and besides these there has been preserved a small code in Scotland termed the Laws of the Picts and Scots, and some fragments of ancient law retained in the hands of the different kings of the race of David I.[157] [Sidenote: Tribal organisation of the Gaelic race.] It is with the Celtic races alone that we have to do in this work, and principally with those of Gaelic race, who alone preserved a separate and independent existence in Scotland; and an examination of all those documents which tend to throw light upon the early social organisation of the Gaelic as well as of the Cymric race leads us to the conclusion that it was not territorial or purely patriarchal, but was based on the community or tribe. Among the people of Gaelic race the original social unit appears to have been the _Tuath_, a name originally applied to the tribe, but which came to signify also the territory occupied by the tribe community;[158] but when we endeavour to ascertain the original constitution of the Tuath or tribe of the Gaelic race, we are met by a difficulty analogous to that which we have to encounter in investigating the history of their language. ‘The formation of the mother tongue belongs to the prehistoric period, and it is a process which, carried on in the infancy and growth of the social state, is concealed from observation. When its possessors first emerge into view and take their place among the history of nations, counter-influences have already been at work, their language has already entered upon its downward course, and we can only watch it in its process of decomposition and alteration, and reach its primitive condition through the medium of its dialects.’[159] So it is with the tribe. We nowhere see it in its primitive form. When it first emerges in the historic period it has already entered upon a course of modification and change. Various influences have been at work, both internal, arising from the natural progress of society, and external, produced from the contact of foreign organisations, to alter existing forms and introduce new elements, and