HOW (W.) and LEIGH (H.).—_A history of Rome to the death of Caesar._ London, 1896. IHNE, W.—_Römische Geschichte._ Leipzig, 1868-90. LONG, G.—_The decline of the Roman Republic._ London, 1864-74. MERIVALE, C.—_History of the Romans under the Empire._ London, 1875-76. MOMMSEN, TH.—_The history of Rome._ Translated by W. P. Dickson. London, 1894. NIEBUHR, B.—_Römische Geschichte._ Neue Ausgabe von M. Isler. Berlin, 1873-74. NIEBUHR, B.—_History of Rome._ Translated by Walter (F.), Smith (W.), and Schmitz (L.). London, 1827-44. PELHAM, H.—_Outlines of Roman History._ London, 1893. PETER, C.—_Geschichte Roms._ Halle, 1881. RANKE, L. VON.—_Weltgeschichte._ Thl. II. (“die römische Republik und ihre Weltherrschaft”). Thl. III. (“das altrömische Kaiserthum”). Leipzig, 1883. SCHILLER, H.—_Geschichte der römischen Kaiserzeit._ Gotha, 1883-87. CHAPTER I THE EARLIEST CONSTITUTION OF ROME § 1. _The Growth of the City_ In the developed political life of Italy there is a survival of a form of association known as the _pagus_[1]—an ethnic or, at least, a tribal unit, which is itself composed of a number of hamlets (_vici_, οἶκοι). This district with its group of villages perhaps represents the most primitive organisation of the Italian peoples engaged in agriculture and pastoral pursuits.[2] The _pagus_ seems to resemble the tribe (_tribus_) of the fully formed city-state,[3] while the _vicus_ may often have represented, or professed to represent, a simple clan (_gens_). In the centre of the district lay a stronghold (_arx_, _castellum_), in which the people took shelter in time of danger. There are, indeed, traditions of isolated units still smaller than the _pagus_. The clan is sometimes pictured as wandering alone with its crowd of dependants.[4] But migration itself would have tended to destroy the self-existence of the family; the horde is wider than the clan, and the germ of the later _civitas_ must have appeared first, perhaps, in the _pagus_, later in the _populus_ which united many _pagi_. The union may have been slight at first, and may often have been based merely on the possession of some common shrine. Much of the civil and criminal law was administered within the family in the form of a domestic jurisdiction which survived in historical Rome; but a common market would involve disputes, and these would have to be settled by an appeal to an arbitrator (_arbiter_) even before the idea of a magistracy was evolved. Lastly come military necessities whether of defence or aggression. It is these that create a power which more than any other makes the state. The mild kingship of the high-priest of the common cult gives way to the organised rule of an _imperium_, and the king, _praetor_ or _dictator_, is the result, the coherence of infant organisation being dependent on the strength of the executive power.