exclusively, of patricians" but voted after infantry of the first class, subordinate to the relatively low-status infantry. Tribal and boundary expansions The Servian reforms increased the number of tribes and expanded the city, which was protected by a new rampart, moat and wall. The enclosed area was divided into four administrative regiones (regions, or quarters); the Suburana, Esquilana, Collina and Palatina. Servius himself is said to have taken a new residence, on the Esquiline. The situation beyond the walls is unclear, but thereafter, membership of a Roman voting-tribe would have depended on residence rather than kinship, ancestry and inheritance. This would have brought significant numbers of urban and rural plebs into active political life; and a significant number of these would have been allocated to centuries of the first class, and therefore likely to vote. The city of Rome's division into "quarters" remained in use until 7 BC, when Augustus divided the city into 14 new regiones. In modern Rome, an ancient portion of surviving wall is attributed to Servius, the remainder supposedly being rebuilt after the sack of Rome in 390/387 BC by the Gauls. Economy Some Roman historians believed Servius Tullius responsible for Rome's earliest true, minted coinage, replacing an earlier and less convenient currency of raw bullion. This is unlikely, though he may have introduced the official stamping of raw currency. Money played a minimal role in the Roman economy, which was almost entirely agrarian at this time. Debt and debt bondage, however, were probably rife. The form of such debts would have had little resemblance to those of cash-debtors, compelled to pay interest to money-lenders on an advance of capital. Rather, wealthy landowners would make an "advance loan" of seed, foodstuffs or other essentials to tenants, clients and smallholders, in return for a promise of labour services or a substantial share of the crop. The terms of such "loans" compelled defaulters to sell themselves, or their dependants, to their creditor; or, if smallholders, to surrender their farm. Wealthy aristocratic landholders thus acquired additional farms and service for very little outlay. Dionysius claims that Servius paid such debts "from his own purse", and forbade voluntary and compulsory debt bondage. In reality, these practices persisted well into the Republican era. Livy describes the distribution of land grants to poor and landless citizens by Servius and others as the political pursuit of popular support from citizens of little merit