Conclusions are hard to draw from the small amount of evidence from the dark past. The light produced gives exciting hints but is rarely illuminating. It would seem fair to say that the cultures of Celtic Europe were not interested to any great extent in ranged warfare. This would fit with an heroic vision of conflict in which small warrior bands competed for prestige and glory.
Barry Cunliffe states that intensifying conflict gave rise to the complex hillforts of Southern England.
|Clay sling bullets|
Though hard to determine archaeologically it does appear that the North of Britain was at relative peace at this time, conjecturally it may be that intense use of missile troops reflects a far more ruthless and political use of martial force than was the cultural “norm” for pre-roman Britain. While the Irish cycles may seem to undermine this hypothesis it should be noted that slings are used by heroes against anonymous armies, supernatural enemies, or a vilified enemy such as a lying charioteer or the rather villainous Queen Medb. Fighting between heroes of rank is by spear or sword.
If this hypothesis is true why then did the sling not come back into use in harder times such as the bitter conflicts with the Vikings? The bow seems to have but one advantage over the sling in that it can be shot more accurately. Modern Balearic Islanders have been hosting slinging competitions for several years, the smallest target zone is a full 50cm across. A size which would completely encompass many archery targets at similar ranges. Sling stones can be thrown by modern slingers over 400m with lead shot being used to out-range stone shot in antiquity. Xenephon notes that slingers were out ranging archers in the retreat from Persia and the deadly efficacy of the sling was noted by many classical writers; “ Soldiers, despite their defensive armor, are often more aggravated by the round stones from the sling than by all the arrows of the enemy. Stones kill without mangling the body, and the contusion is mortal without loss of blood.” (Vegetius) or “But when Hamilcar saw that his men were being overpowered and that the Greeks in constantly increasing number were making their way into the camp, he brought up his slingers, who came from the Balearic Islands and numbered at least a thousand. By hurling a shower of great stones, they wounded many and even killed not a few of those who were attacking, and they shattered the defensive armour of most of them. For these men, who are accustomed to sling stones weighing a mina (approximately 600g), contribute a great deal toward victory in battle [...] In this way they drove the Greeks from the camp and defeated them.” (Diodorus Siculus).
The words of the classic authors are given weight by the presence of Roman Army surgical probes for removing sling bullets. Slings can also be used to give a similar rate of shot as a good archer though the off hand can also be used to hold a shield giving more protection to the slinger with only a small reduction in rate of shot.
Sling bullets are readily available and where made from clay or lead are very simply fabricated. Slings themselves are readily fashioned from any fabric or leather and would be easily within the means of any person who wanted one. The bullets are easily transported and in dire emergency rocks can be picked up from the ground and used. Arrows are longer and both arrows and bows require considerable time and material to make. Indeed in the context of large armies and sieges a sling actually seems to have no disadvantage compared to a bow. Note however that classical armies used both slingers and archers.
In a combat of smaller groups of men perhaps more spread out as part of raiding, skirmishing or piratical groups a greater degree of accuracy might be required or at least be advantageous. A bow would have the advantage of a slinger in such a situation the bow can also be shot from a kneeling or crouching position and requires far less movement from the shooter. This potentially makes a bow a better choice for ambushes.
|Roman employed slinger from Trajan's column|
|Balaeric target plans (from slinging.org)|
The last point is that in Europe at least archers also doubled as light infantry; after expending their ammunition archers would then engage in hand to hand combat. This was decidedly not the case in the ancient world where specialist slinging troops were not used for melee. Battles in the ancient and medieval world always (except in very unique conditions) ended up in at least some kind of hand to hand fighting. It may well be that specialist troops were too logistically expensive for dark age and later societies and that it was better to get lighter troops to bring along bows rather than employ specialist types.
Ultimately all these points are conjecture and it is enough for this work to say that slingers were not used in any number by the Gaelic world in a military context. I suspect that the sling fell out of favour as agricultural practises changed and the sling became little more than a bird scarer or a toy for bored shepherds rather than an essential agericultural tool. While the bow ,a more user-friendly technology, was recalled when missile troops began to be used more in combat the knowledge base for the sling was lost and it made only sporadic appearances in history thereafter.