Tullius ordered all the Romans to register their names and ages, with those of their parents, wives and children, and the place of their abode, either in the city or the country. At the same time he enjoined them to give in upon oath a just valuation of their effects, on pain of being whipped and sold for slaves if they failed in registering all these particulars. From this register he formed his plan for a regular and general militia, which was invariably followed by the Romans, until the time of Marius. To effect this he divided the whole body of the citizens into six classes. The first class consisted of those whose possessions amounted to a hundred _minæ_.[245] These he armed in the completest manner, and divided into eighty centuries; forty of which, composed of the younger men, were appointed to take the field in time of war; the other forty were assigned for the defence of the city. To these eighty centuries of heavy armed foot he added eighteen centuries of horse, selected out of those who had the largest estates, and were of distinguished birth. Thus the first class contained ninety-eight centuries. The second, third, and fourth classes consisted each of twenty centuries only, and were composed of citizens, whose effects were estimated at seventy-five, fifty, and five and twenty _minæ_; and their arms were lighter according to their respective classes. To the second class he added two centuries of armourers and axe-men. To the fourth class two centuries of trumpeters and blowers on the horn, which contained the martial musick of the army. The fifth class consisted of those who were worth twelve _minæ_ and a half, which he divided into thirty centuries, armed with darts and slings only, and were properly irregulars. The sixth class, which was by much the most numerous, was comprehended in one century only, and consisted of the poorest citizens, who were exempted from all kind of taxes, as well as all service in the army.