While medieval society as a whole relied more heavily on religion and devotion as a protection against environmental hazards than is the case today, proactive risk management was common too. Indeed, mitigation, protection and adaption, the three main categories of hazard-reducing practices today, were all applied during the Middle Ages (Smith and Petley 2009, pp. 72–101).

Hazard mitigation

Hazard mitigation, defined here as sustained non-structural actions taken to reduce or eliminate long-term risk to people and their property, was a familiar concept. Medieval communities could be proactive both in their management of environmental risks and while ensuring recovery from their longer-term effects. After the 1333 flood in Florence, the city authorities formed a committee to oversee the repairs, and they lowered taxes on imported foodstuffs and organised tax relief for those in need, facilitating the distribution of food supplies. Public services were restored by constructing a temporary bridge over the River Arno, and weirs and mills, thought to be to blame for the flooding, were banned close to the city (Schenk 2007). Measures of this sort, including structural assessments, financial relief and rehabilitation, were repeated in many other contexts (e.g. Kershaw 1973; Guidoboni and Ferrari 1995; Guidoboni and Ferrari 2000). During the course of the medieval period in London, there is evidence that responsibility for action moved away from the authority of the monarch towards the citizens themselves (Keene 2011), whereas in continental Europe civic authorities took a more central role.

A key aspect of risk mitigation in contemporary society is the sharing of potential costs, and cooperative and collective endeavour were a particular feature of medieval life. From the great households down to the most modest families, neighbours and friends exchanged gifts and engaged in acts of charity. When in 1318 the English king made a grant of alms to the Benedictine convent of Elstow, he did so ‘out of compassion for the state of their house which is so greatly impoverished by the scarcity of the past years’ (Kershaw 1973, p. 30). He might have added that to imitate Christ in the performance of charity was considered a most effective manner of attaining salvation. At other times, affected communities pleaded their own case when hard times befell them; the people of Mataró (Spain), for example, petitioned their bishop for a licence to collect alms for the repair of their churches after an earthquake struck in 1448 (Salicrúi Lluch 1995). In rural areas, manorial courts ensured that some modest resources were provided for villagers in need (Dyer 1989, pp. 234–257; Richardson 2005) while food alms were distributed by hospitals, direct from the dining tables of the wealthy, and as funeral bequests (Woolgar 2011).

All these charitable acts, large and small, provided relief in the event of misfortune but of far greater consequence were the fraternities and religious guilds that offered help in-kind, loans or stipends to their members. Most of the urban population of later medieval continental Europe would have belonged to such a confraternity; in the mid-sixteenth century, Toledo boasted 143 groups for its 60,000 inhabitants, and they were quickly transformed into powerful and wealthy institutions through the many donations and bequests they received (e.g. Cossar 2001 for Italy; Flynn 1985 for Spain). The main purpose of a confraternity was to sponsor devotional activities and distribute charity to the poor in the form of cash, bread, wine and salt. Like the English king, this was the vehicle through which their members hoped to achieve personal salvation. In the case of individuals who had fallen on hard times as a result of shipwreck or storm damage, the confraternities did not offer to replace lost assets, but could draw upon funds to which members had previously contributed—a primitive form of social security (e.g. McRee 1993). This has some similarities to the modern business models of the reinsurance industry, which tries to ensure that premiums will balance insurance pay-outs over long periods of time, with profit being generated primarily through investment return between disasters. Interestingly some confraternities continue to exist today—for example, the Archiconfraternity of the Misericordia, which was founded in Florence in 1244, remains a key civilian protection force in Italy.

Rather than sharing economic loss across the community, another important principle was to spread the burden of loss over a longer period in order to reduce its immediate severity. Across medieval Europe, very large barns on monastic estates provided centralised storage for unthreshed grain (Brady 1997), while supplies of threshed grain were piled in cellars and upper storeys as well as in civic granaries. Margins were tight and quantities insufficient to ride out a long crisis (Claridge and Langdon 2011), but localised shortfalls could be overcome temporarily by releasing a portion of what was held in store. An alternative, if costly, strategy was to purchase grain from outside the local area. For example, in the winter of 1316 English merchants travelled far afield to buy up stores of corn, and even went abroad (Kershaw 1973). This option was favoured too when impacts were geographically widespread and demand could not be met locally, for example after the volcanic eruption of 1258–1261 when grain was shipped from Germany and Holland into London (Stothers 2000). Episodes like these were easily exploited and, to prevent this, merchants were prohibited from buying and reselling the corn (Keene 2011). In later centuries too, there were those who envisaged permanent stockpiles of grain to be sold without thought to profit. The Leadenhall granary, built in the 1440s in London, was one such project designed to make the capital less sensitive to famine (Samuel 1989).

Hazard protection

Hazard protection, used here to describe structural responses designed to reduce risk, is also well documented for the medieval period. In the case of flooding, floor levels inside buildings could be raised, as excavation proved in the transept of the abbey church at Bordesley Abbey in Redditch (England; Rahtz and Hirst 1976, pp. 70–72). At the monastery of Clara-a-Velha in Coimbra (Portugal), the flooding from the nearby River Mondego was so frequent after 1330 that the nuns were forced to raise the interior levels of their monastic buildings repeatedly, eventually having to construct a unique elevated storey inside their church (Fig. 9) before finally abandoning the site in 1677 (Cunha et al. 2000). Other kinds of investments too needed protection from floodwaters. At Romney Marsh on the coast of southern England, Canterbury Cathedral Priory invested in sea defences and buildings to protect both its livestock and the soils so studiously improved with leguminous crops and dressings of lime and manure (Gross and Butcher 1995). Archaeological features here and elsewhere range from large-scale engineering such as embankments and wind-powered pumping engines (especially in the Netherlands) to more minor projects such as the walls, sluices and ditches sometimes picked up by archaeological earthwork and contour surveys (e.g. Chapman 2010, pp. 147–148).

Fig. 9 The interior of the monastic church at Clara-a-Velha in Coimbra (Portugal). To escape the floods from the nearby River Mondego, the nuns raised the floor of their church and finally built an upper storey to span its full length. Once they had relocated their altars, the celebration of Mass could continue. Here, people are seen on the partially reconstructed upper storey, and the staining from high water levels is visible on the supporting columns below (picture courtesy of Alejandra Gutiérrez) Full size image

When rebuilding took place after a disaster, structural modifications were sometimes introduced. The ninth-century town wall at Andújar (Spain) was remodelled and reinforced after the 1170 earthquake (Peláez et al. 2005), while excavation in SW England at the church of St. Michael on Glastonbury Tor revealed that rock fissures had been blocked up with mortared material when the church was rebuilt after being flattened in an earthquake in September 1275 (Rahtz 1970). Disaster could open up opportunities for investment and rebuilding, even lay down a statement of confidence, but vested interests invariably led owners to disregard the prospect of further calamities (Ambraseys 2006), particularly when hazards were deemed to be preventable. Such optimism could be wildly misplaced; thousands of hectares of reclaimed marshland were lost along the Thames Estuary in the later medieval period, for example, while the inundation of 300 km2 of embanked land south of Dordrecht (Netherlands) in 1421–1424 was blamed on a lack of dike maintenance and specifically on peat extraction (Galloway and Potts 2007; Gottschalk 1975). Maintenance, it seems, had been neglected. For a variety of reasons, people living in vulnerable areas could undoubtedly underestimate the risk of major events or the effectiveness of their protection. In other cases, they showed extraordinary resilience. Excavations at Kootwijk (Veluwe, the Netherlands) provide telling evidence of the defiance of villagers as they fought against drifting sand by erecting long screens (>100 m) to prevent their fields and settlements being smothered (Heidinga 1987; van Doesburg 2009). When wind-blown sand overwhelmed settlements, it led to rebuilding further and further inland. The original church at Kenfig in south Wales was replaced in 1262 and a third built in a safer location at the end of the fifteenth century (Morris 1989, p. 340).

Hazard adaptation

Adaptation to hazards involves a change of behaviour so that a risk can be tolerated and the timely identification of hazards is central to this. When the tower houses of Pisa were destroyed in a fire in 1158, the civic authorities sought to minimise further risk by ordering the demolition of wooden porches and balconies that had contributed to the fire spreading. Elsewhere in Italy chimneys were to be built out of brick by the mid-fourteenth century, thatch was to be substituted with non-flammable tiles, and it was forbidden to store large quantities of combustible products; precautionary measures like these could be found in many countries (Tragbar 2006; Jack 1979). In England, the investigation of incidents of flooding along the Thames estuary fell to royal commissions which were made up of local landowners and court officials; some 153 operated between 1280 and 1449 reacting to concerns voiced over the condition and organisation of coastal or river defences (Galloway and Potts 2007). In those regions where environmental hazards were a regular occurrence, there was greater community preparedness. In the Netherlands, both Holland and Utrecht had developed centralised mechanisms to manage their dike systems before 1250, a solution that was encouraged by an unusual set of circumstances; the disproportionately high maintenance and repair costs combined with a fragmented pattern of landholding required fuller coordination of responsibilities (Tol and Langen 2000).

Nevertheless, when disaster hit, if the threat was sudden, temporary and localised, risk judgements had to be intuitive and immediate. Thus, Florentines escaped the 1333 floods by climbing onto the roofs of their houses (Schenk 2007), while in Trieste the citizens climbed the slopes of San Giusto to avoid the tsunami that followed the West Slovenia earthquake in 1511 (Tinti and Maramai 1996). Sometimes, there was help from others, so that in Lucca (Italy) in 1346 carpenters, stonemasons and bricklayers were required to demolish houses to prevent urban fires spreading (Tragbar 2006). In the aftermath, many were forced to look to their own devices, reducing the size of their households, or selling possessions and land in order to raise money for the purchase of essential foods (Keene 2011). Some moved away like the inhabitants of Vera La Vieja who decamped into nearby fields after the 1518 earthquake. They were responding, as many others did at other times and places, by temporarily shifting down to subsistence levels and saving their lives. Sometimes a minor relocation like this could develop into something more permanent and thereby modify the morphology of a settlement, as happened in flooded villages along the fen margin of East Anglia (England) when fourteenth-century manor houses were relocated uphill (Ravensdale 1974). But some disasters also encouraged more permanent migration. If the impact was widespread, as it was in the case of the Black Death, there were new opportunities for employment and better housing, and so people moved to take advantage. Siena and Orvieto (Italy) were not alone among civic authorities in passing emergency legislation to restrict population movements (Cohn 2007). In the case of rapid onset events such as floods or earthquakes, where the effects tended to be more localised, the devastation was rarely total or so widespread. Nevertheless, archaeology does provide some case studies of new settlements laid out after disasters (e.g. Taylor 1983, p. 171), one of these is New Winchelsea (England) which was laid out in its present hilltop location after two great storms in 1250 and 1252 breached the shingle barrier on which the port of Old Winchelsea once stood (Martin and Martin 2004). Another example is Vera La Vieja where not one of the 200 houses remained standing after the earthquake of 1518. A contemporary assessment of conditions at the site cites the difficulties of building solid foundations for housing, the poor condition of the castle, the cost of clearing rubble, the drying up of water from the spring, and the vulnerability of the defenceless survivors to North African raiders (Olivera Serrano 1995, p. 55). For these reasons, the survivors were eventually moved from their temporary encampments to a new site nearby complete with 140 new houses, church, bakery, square and town walls (Villanueva Muñoz 1986–1987).

Even when living conditions were deteriorating, archaeological studies show that settlements could still flourish and everyday activities might even intensify, as they did in transhumant and mining communities in the French Alps during the onset of the ‘Little Ice Age’ (Walsh 2005). The lesson is that notions of risk are contingent on time and place and other factors were often in play when the survivors of disasters were permanently relocated. For example, it was unfavourable economic conditions that hampered the recovery of Syracuse in the two decades following an earthquake in 1542 (Boschi et al. 1995). Likewise, the archaeological evidence from England suggests that there was no direct or exclusive link between settlement desertion and disaster, whether that be plague or climatic deterioration (e.g. for Hound Tor and the climate debate, see Beresford 1979; Wright 1976; Austin and Walker 1985; Allan 1994). Several interrelated causes were usually to blame, such as weakening demographic pressure (Astill and Davies 1997, pp. 149–150 for Eastern Brittany in the fifteenth century) or tenurial circumstances (Taylor 1983, p. 199). Unless the landscape was dramatically altered, as it might be after a landslide, subsistence agriculture was usually able to continue, and people stayed where they were. Even when medieval Sicilians living on the flanks of Mount Etna were repeatedly threatened by volcanic eruptions and earthquakes, their ruined settlements were invariably rebuilt on the same site or close by (Chester et al. 2005). At Shipston-on-Stour in Warwickshire (England), nearly two-thirds of the town was destroyed in a fire in 1478, but as the records of Worcester Cathedral show, the town was rebuilt within 5 years and its trade flourished (Dyer 1992/1993). This is not dissimilar to modern responses to risk, in which people remain generally unwilling to relocate even where the levels of hazard demonstrably exceed levels that are considered to be tolerable under normal circumstances. Alexander (1991) describes such geographical inertia as a key response to risk in modern societies, even where no mitigation is available or practicable.

Aside from these direct responses to disaster, several traditional features of the medieval agrarian and household economy across Europe served to buffer risk, particularly from routine ‘slow-onset’ hazards such as harvest failures. Diversification was one answer, for example planting vegetables and fruit in domestic gardens (Harvey 1981), an activity for which there may be archaeological evidence in the form of land parcels, intensive manuring, hand dug furrows and plant remains (e.g. for Cookstown, Co. Meath, Ireland; Murphy and Potterton 2010, p. 353). A judicious mix of crops also reduced the risk of failure; for example rye, barley and oats were planted as well as wheat, which itself came in different varieties (rivet, bread, etc.). The consumption of ‘fall-back foods’ represents a second form of diversification, and in the eleventh century, these varied from roots to herbs and even natural clays mixed with a little flour to make bread (Le Goff 1978, pp. 22–23). In the Mediterranean, it was the chestnut which provided an inferior type of flour for bread (Delano Smith 1979, pp. 215–217). Elsewhere, crops were selected to cope with environmental stresses (oats in N Europe, for example, were less affected by excessive rainfall), and in some lowland areas, the deliberate scattering of arable strips across different soils helped to share the risks of a poor harvest across the whole community (e.g. Fenoaltea 1975; McCloskey 1991; Cosgel 1990; Bekar and Reed 2003).

Other means of buffering risk was to intensify land use; for example, the careful management of woodland could create a renewable resource, and crop rotations on arable land acted to rest the soil. These practices enabled the medieval farmer to extract more from existing areas of agricultural exploitation. Archaeology also reveals how medieval communities shared their landscapes. The way in which administrative territories were shaped to converge on valuable resources such as woodland or pasture is one example, albeit with earlier origins (Aston 1985, pp. 42–43). Another is the sharing of water in arid environments; in parts of medieval Spain, villages were dependent for their agrarian water supply on a network of hydraulic or gravity-flow canals whose administration depended wholly upon cooperation between upstream and downstream irrigators (e.g. examples in Kirchner 2010; Gerrard 2011). At the same time, pressure on food resources could also be alleviated by extending the zone of cultivation and the reclamation and transformation of coastal wetlands and the drainage of freshwater backfens are well documented during the Middle Ages by landscape archaeologists in north-west Europe (Rippon 2000, 2004). Recolonisation intensified during the twelfth and thirteenth centuries, for example in north Holland and in newly embanked areas such as the German marshes. The construction of sea walls and fen banks, the digging of artificial channels and canals for drainage, and the establishment of villages, farmsteads and granges were all part of this process. Paradoxically, extensification in reclaimed coastal areas also played a major role in putting medieval communities at risk.