In Gaul, clientship was the principal thread of political life. It was a personal bond between two men of unequal standing: the greater offered protection and support, the lesser gave loyalty, service and, above all, a following in war.^[33][3] Nico Roymans describes it as a form of patronage, a tie that was reciprocal, in that each side owed the other something, but unequal, in that the two stood on different rungs of society. The command of a large body of clients was the foundation on which a nobleman's power rested.^[12] Such ties reached from the follower of a single lord up to whole peoples, a weaker tribe placing itself in the clientela of a stronger, and together they ran through the whole of Gaulish public and military life.^[1][34]

Within a great man's following, Caesar and the Greek writers distinguish two grades of dependant. The heavier grade were the ambacti. Venceslas Kruta describes an ambactus as a man, free by birth, who for payment or to clear a debt gave up his own standing at law to a rich and powerful patron, who from then on answered for him in every legal matter. He was close to a serf, though not, as Caesar believed, the outright property of his lord. He still carried arms, the mark of a free man, and in return was bound to follow his patron to war. The word was later rendered in Latin as servus ('slave'), showing how heavy this dependence could grow.^[23] The lighter grade were the clientes proper, who kept their own standing at law but paid higher dues and owed their patron homage and service in peace and war.^[3] Because cliens was also the ordinary Roman word for any dependant, it serves in the sources in two senses at once, naming both the relationship as a whole and, more narrowly, this freer grade set beside the ambacti.^[3] The Greek ethnographic tradition likewise reports at least two grades of client, one more respectable than the other.^[35] Beyond these two ordinary grades stood an extreme form of the tie, the sworn soldurios, who devoted his very life to a chief. This bond is recorded among the Aquitanian Sotiates, whose chief Adiatuanus was attended by a body of soldurii sworn to share every good thing of his life and, if he met a violent death, to die with him or take their own lives.^[16][28] As it was sealed by an act of devotio and carrying the duty to follow the patron even into death, Kruta treats it as an intensified form of the ambactus relationship. He notes that the same custom was widespread among the Celts of the Iberian peninsula.^[36]

Roymans distinguishes three levels within this web of patronage. The first was clientship between noble leaders and people of lower rank, free and unfree, who lived mainly by their own farming but could also be called on for military service. The second was clientship within the nobility itself, seen in the armed retinue, or Gefolgschaft, of a leader and in the political factions (factiones) that Caesar describes, such as the rival pro-Roman and anti-Roman parties of the Treveri under Cingetorix and Indutiomarus. The third was clientship between whole peoples, as when many tribes joined the clientela of the Remi during the war. The stacking of these ties produced what Roymans calls 'clientage pyramids', networks of vertical dependence that cut across tribal boundaries.^[1]

A nobleman's importance was measured by his following. Polybius reports that a Celt was reckoned by the number of his clients and friends, and that friendship was the value most prized.^[2] Kruta observes that the prestige and legal weight of a high-ranking aristocrat depended on the number of ambacti and clients attached to him.^[3] The relationship was material and social and, as Caesar notes, also religious in its basis.^[28] The retinue was kept up by open-handed generosity and, where need be, by plunder. Roymans notes that Dumnorix was constantly attended by a large private retinue of horsemen whom he maintained at his own charge, his popularity resting on his lavish giving (largitio).^[37] David Rankin cites Orgetorix, who is said to have had a familia together with many clients and dependants, whose loyalty was the basis of his power among the Helvetii.^[38] In the same passage Caesar sets three grades within Orgetorix's following, the familia of his household, the clientes proper, and his debtors, an order Brunaux reads as one of decreasing personal closeness.^[39] Debt was itself a road into dependence. Caesar reports that commoners crushed by debt, tribute or the exactions of the powerful gave themselves into servitium to the nobles. Alain Daubigney treats the debtor (obaeratus) of the Helvetian threefold group of familia, clientes and obaerati as a standing means by which the powerful drew clients from the common people.^[40]

Clientship was accordingly the central mechanism of aristocratic power, though not the only one. Kruta notes that the Gaulish aristocracy of the 1st century BC controlled political and economic life not only through clientship but also through taxation and a monopoly on the striking of coin, as in the case of the Aeduan Dumnorix.^[34] The bond could also be enforced by force: Rankin cites Caesar's report that Vercingetorix raised his army by threats of death and mutilation.^[38] Not long before Caesar's time it had been the custom to burn a chief's clients and slaves on his funeral pyre.^[41]

The Roman conquest turned on these ties. Kruta notes that Caesar exploited the weakness of the clientship links and alliances that held the Gaulish coalitions together, and that after the conquest Rome favoured the freeing of small peoples once bound in clientship to great civitates, which may explain the appearance of peoples unattested in Caesar's day such as the Tricasses and the Catalauni.^[4] Territory itself could be spoken of as a client's: the reputedly impregnable stronghold of Uxellodunum is said to have belonged to the clientela of the Cadurcan Lucterius.^[42] Under the early Empire the language of clientship still described Gaulish society: in AD 68 Vindex was supported by many chieftains and their thousands of clients.^[43]

The Greek and Roman writers credit the Celtiberians with two native institutions of personal dependence, hospitium and clientship.^[44] Hospitium was a pact of hospitality: a solemn and often hereditary bond of mutual guest-friendship between two communities, or between a person and a community, recorded on inscribed bronze tokens (tesserae hospitales) written in Iberian and in Celtiberian. Manuel Salinas de Frías treats it as genuinely native to Spain, distinct from the Roman institution of the same name, and shows that, as wealth came to differ between the parties, a pact of this kind could harden into a relationship of dependence close to clientship.^[45] Martín Almagro-Gorbea and Alberto Lorrio treat personal clientship as a structural feature of Celtiberian society which, fitted to a stock-raising economy, gave the whole society a warrior character. In their account a 'clientelar army', a force raised from a chief's own clients, marks a stage between the earlier war-bands and the later town and mercenary armies.^[46] In so competitive a society, the number of a chief's clients was a mark of his standing, and army leaders were drawn from the nobility, to whom picked warriors were bound by solemn ritual.^[47]

A distinct and extreme form of the bond was the warrior-consecration that the Roman writers call devotio, by which warriors pledged their lives to a chief and might not outlive him. It is attested among Celtiberians, Lusitani, Vettones and Cantabri, and has been likened to the Gaulish soldurii mentioned by Caesar.^[27] Salinas links the bond to the Iberian custom, reported by Strabo, of men consecrating their lives to the leaders they attached themselves to.^[48] He traces it under Sertorius, who according to Plutarch was followed by many thousands of Hispani sworn to die with him, and holds that the consecration assumed the existence of underworld gods who could accept the devotee's life in place of the leader's.^[49] A war-retinue (Gefolgschaft) of picked warriors served closely under the great chiefs. The personal name Ambatus is very common in Celtiberian inscriptions, and some scholars connect it with the Gaulish ambacti and read its frequency as a trace of the same institution, though the link is disputed.^[50]

The size such followings could reach appears in the literary record. The Celtiberian prince Allucius is said to have thanked Scipio by presenting him with 1,400 horsemen drawn from his own clients.^[51] Salinas cites the story of the chieftain Thurro, who in 179 BC put himself at the disposal of Tiberius Sempronius Gracchus after Gracchus had spared his captured sons, as showing that clientship was practised among the Celtiberians before the Roman conquest.^[52] Rome then set out to draw these mounted elites into its own following, so that in time they were absorbed into the Roman clientship system.^[50] Certain dependent settlements have been read as 'client settlements' typical of Celtiberian society.^[53]

The early Irish law tracts describe clientship in legal detail and distinguish two kinds of client, the base client and the free client. Thomas Charles-Edwards describes the institution as one form of the lord-and-vassal relationship common to medieval Western Europe: it was made by a grant of livestock, or sometimes of land, in return for food-renders and personal service from the client. What most set it apart from the manorial lordship of medieval France and England was that the grant was normally of cattle rather than of land.^[6] Fergus Kelly notes that holding clients gave a lord standing as well as food-rent and services, while in return the client received from his lord an advance of stock or land with which to support himself and his dependants, and could look to his lord for backing at law.^[18]

Nerys Patterson places clientship at the centre of the political economy of the túath (the small kingdom), the instrument through which lords built and held power. A single pattern of gift and return ran through the whole hierarchy, from the túarastal, a stipend of costly gifts bestowed by an over-king and repaid in tribute by an under-king, down to the fief of cattle advanced to a base client, each grant binding the receiver to a fixed return.^[54]

In base clientship the lord advanced to his client a fief, usually of livestock, called the taurchrecc ('fore-purchase'). Its size varied with the client's rank, an ócaire ('small farmer') receiving a fief worth 16 séts (a sét being a standard unit of value, reckoned in cattle or silver) and a bóaire ('strong farmer') one worth 30. The client paid a yearly food-rent (bés tige) in proportion to the fief, and if he paid it in full for at least seven years the fief became his own on the lord's death. The lord also secured the base client's honour-price (lóg n-enech, 'the value of a face', the measure of a free person's standing at law)^[55] by advancing him goods called the séoit turchluide ('chattels of subjection').^[56] The fief advanced to a free client was called instead the ráth.^[57]

A lord's own honour-price was reckoned in part from his clients, so that an aire déso, the lowest grade of lord, took his honour-price of ten séts from his holding of five base clients.^[58][59] The relationship reached into the church as well, for an abbot, like any secular lord, could advance a fief to monastic clients who answered with rent and service.^[60]

Within the insular Celtic world the institution appears to be peculiar to Ireland. Charles-Edwards finds no system in Wales to match Irish base clientship. There free native descent conferred nobility of itself, a lord's position rested on food-renders rather than on a grant of cattle, and the render-paying taeog was, unlike the Irish base client, unfree. He rejects the argument of D. Howells that the Welsh law-texts keep traces of clientship on the Irish pattern, while allowing that it may none the less be correct.^[8]