While Ireland is somehow outside the main epicenter of these invasions, it still remains vulnerable. Round towers could thus provide the necessary defense around a monastery or church.
Some of the elements that could support such a defensive function include the fact that these towers were built of stone even in a period when stone defensive constructions were not yet the norm throughout Europe (the Norman keeps, for example, would become the usual defense fortification only in the 11th century). At the same time, the round towers were equipped with wooden ladders on which the people could claim inside and, allegedly, pull up the wooden ladder, making it almost impossible for the attacker to either climb inside or in any other way, endanger the life of the people inside the round tower.
One of the important arguments used against the belief that round towers had a primarily defensive function comes from the ladder itself. The ladder would have been made of heavy wood and would generally be as long as thirty feet.
Both these factors would have made it almost impossible for a wooden ladder to be pulled inside, especially given the accessibility issue inside a round tower. Potentially, only something as flexible as a rope ladder would make sense as to being able to be pulled inside, but certainly not a wooden ladder. At the same time, being located near monasteries and churches, it would be difficult to imagine elderly monks completing all the physically challenging task involved with using the round tower in its defensive function.
Additionally, the doorway, providing access to the round tower, showed a different perspective than would have seemed reasonable if the towers had a primarily defensive function. As such, in some of the round towers, the doorway was on the ground or very close to the ground, and this was noticed in some of the round towers that were otherwise built in regions that were more vulnerable to attacks and invasions. On the other hand, in other cases, the doorway was above ground, but history has not mentioned any such attacks in the area.
The historians and archaeologists remained significantly split on the issue of the defensive function in the case of round towers. Some historians tended to see this as a secondary function, while the corroboration of the time these towers were possibly built with the Viking invasions made other historians argue more strongly over the defensive function of the towers.
There seem to be more historians arguing for the belfry use of round towers in Ireland. One of the arguments in this sense is related to the existence of similar belfries, called campanile, in Italy, around the same time as the round towers of Ireland, perhaps the most well-known example in this sense being the Tower of Pisa. This argumentation would reasonably make sense, as most of these round towers were discovered either next to the ruins of some church or monastery or actually enabled the discovery of such a religious ruin.
Nevertheless, there are other questions that arise from assuming this primary function for the round towers in Ireland. First of all, the round towers seem to be completely out of proportion with the surrounding architecture, notably the church or monastery they were built next to. In some cases, the difference of height from construction goes well over thirty meters.
In my opinion, this is not necessarily an argument that can stand against the specified function of the Irish round towers. Roger Stalley has mentioned the Tower of Pisa as an example of an Italian campanile that would be considered an appropriate comparison in Italy. However, if we consider the Tower of Pisa and the way this is located in the Campo dei Miracoli, the conclusion is simple: the tower is significantly higher than the church situated next to it. Further more, this stands for almost any example we wish from the Italian architecture, ranging from the Church of San Marco in Venice to the Church of San Giovanni e Paolo in Rome.
Another argument that is brought into discussion by assuming this primary function is related to the design consistency. Despite small influences brought about by the Romanesque style, these constructions remained reasonably unaltered in design and architecture throughout history, despite the European architecture developing in this period of time.
In my opinion, this is not necessarily a problem that arises. Ireland, during the period of time when we assume that these towers were built, was somewhat isolated from the cultural trends developing on the continent. The small changes in the design and architecture of the round towers in fact reflected the small participation of Ireland to the European cultural exchanges.
The form of the round towers however would still continue to intrigue, despite these different aspects and explanations. Different particularities of the construction, such as the conical roofs of stone and the raised doorways, still provide intriguing elements for such an explanation. Some have shown the roofs, for example, as a way of preventing the continuous dangers of lightning and a mean of isolating the construction below. The explanation stands as a technical explanations, however, there are numerous others that could be used as well.
One of the potential eclectic conclusions one can draw is that the round towers in Ireland provided all of these functions, overall, at different periods of time. At the time of Barbaric invasions, when Ireland was vulnerable to invasions from the Vikings, for example, round towers certainly provided a defensive function. The strong stone towers could be, by themselves, a strong deterrent to the invading parties. At the same time, as a corollary to the defensive function, the round towers could well function as treasuries, because the strong stone and difficult accessibility made them plausible in this role.
At the same time, it is obviously reasonable to believe that the Irish round towers were also closely related to several monastic and religious functions. The most obvious of them seems to be that of a bell tower, especially given the widespread of this type of towers throughout Europe during the period of time starting with the 10th century. Nevertheless, one will also need to take into consideration the reasonably little influence that Europe actually had on Ireland during this time.
One of the very difficult challenges remains dating the Irish round towers. Carbon dating is useful in determining the period of time when these constructions were made, despite the interval of time being extremely generous. However, it helps point to somewhere around the 9th to 10th century as a reasonable timeframe when the round towers began being produced in Ireland, and not anywhere towards Antiquity.
1. Stalley, Roger. Irish Round Towers. Country House, Dublin.
2. Wakeman, William. 1848. Archaeologia Hibernica: A Hand-book of Irish Antiquities.
3. Bonwick, James. 1894. Irish Druids and Old Irish Religions.
4. Petrie, G. 1845, reprinted in 1970. The Ecclesiastical Architecture of Ireland: An Essay on the Origin and Uses of the Round Towers of Ireland. 2nd edition.
5. Stokes, M. 1878. Early Christian Architecture in Ireland.
Stalley, Roger. Irish Round Towers. Country House, Dublin.
Wakeman, William. 1848. Archaeologia Hibernica: A Hand-book of Irish Antiquities.
Bonwick, James. 1894. Irish Druids and Old Irish Religions.
Stalley, Roger. Irish Round Towers. Country House, Dublin
Petrie, G. 1845, reprinted in 1970. The Ecclesiastical Architecture of Ireland: An Essay on…