Norse and Aztecs questions and answers

Climate can cause a change without explaining the outcome by itself. Warmer centuries widened the opportunity for farming in Norse Greenland; cooling after 1275–1300 narrowed it. Yet Iceland endured the colder period, and Thule Inuit expanded into Greenland while the Norse withdrew. Different food and tools made survival possible under cold conditions. Even the evidence of physical change differs by location: Lake 578 records drying near a farm, while the summit cores record conditions high above the settlements. Historians study vulnerability by asking how population, trade, technology and choices exposed people to a pressure or helped them withstand it. The same shock could be an inconvenience to one society and a catastrophe to another.

READ CHAPTER 1 — Medieval Warm Period and Little Ice Age →

Both belong in the explanation. Without a seaworthy, shallow-drafted ship, ambition could not have carried crews to Lindisfarne, Dublin or Iceland. Yet similar vessels existed in Scandinavia for a century before 793. Why were they then used for expansion? Historians point to scarce land, young men's need for marriage wealth, competition among chieftains and incoming Islamic silver, while disagreeing about their relative importance. Written accounts often come from victims and say little directly about Scandinavian motives. The ship itself also depended on social organization: Lise Bender Jørgensen's estimate of decades of women's labor for a warship sail shows what farming communities had to supply. A motive to sail and the capacity to equip a voyage worked together.

READ CHAPTER 2 — Viking expansion and the longship →

For more than 300 years the Althing helped armed chieftains make law and settle disputes without a king, army or taxes. The peaceful adoption of Christianity in 999 or 1000 shows how much an agreed procedure could accomplish. Yet a judgment depended on the winner’s followers for enforcement. When wealth and power accumulated in a few great families in the thirteenth century, that dependence became dangerous: rivals fought the civil wars of the Sturlung Age and accepted the Norwegian king. The institution had worked under a rough balance of power and struggled when that balance changed, a problem no medieval assembly had fully solved. It nevertheless survived as a symbol and later as a parliament.

READ CHAPTER 3 — Settlement of Iceland →

The evidence points more strongly to the resources of the society than to a failure of its ships. Norse crews crossed to Newfoundland, repaired vessels and built accommodation for perhaps 70–90 people at L’Anse aux Meadows. Keeping a distant colony supplied and defended was another undertaking. Greenland may have had only 2,000–2,500 inhabitants, and a long voyage separated it from the base. The sagas describe conflict with Indigenous people who were numerous, organized and fighting on their own ground; Norse weapons gave no decisive advantage. Distance made reinforcement and supply harder, while a larger population might have absorbed losses and long voyages more readily. Historians weigh conflict and logistics differently, and the evidence cannot establish that numbers alone decided the outcome. The ships carried this society farther than its resources could readily sustain a community.

READ CHAPTER 4 — Vikings in Greenland and Vinland →

The Little Ice Age made life harder, but it did not act alone. Cooling and drying narrowed the margin for producing hay, and drift ice made voyages more difficult. The Norse responded by obtaining much of their food from the sea, especially seals; Inuit expansion in the same centuries shows that people using different technology could live in Greenland. At the same time, weaker ivory trade, plague in Norway and the loss of regular shipping reduced the income and contact on which the colony depended. Following Dugmore and colleagues, most scholars describe a convergence of pressures on a community too small to absorb them all. Evidence for orderly farm departures suggests that many people chose to leave. Climate could work slowly, narrowing alternatives until departure became sensible.

READ CHAPTER 5 — Why the Norse abandoned Greenland →

The answer depends on the kind of significance we have in mind. Ships made settlement and exchange possible, carrying people to Iceland and Greenland and later carrying fish and grain. Their building tradition lasted into the twentieth century. Stockfish had the greatest economic weight after about 1100, linking a cold sea to lasting markets in England and the Hanseatic towns. The Althing has a different claim: Iceland’s tradition of law and assembly outlived independence and helped shape its modern parliament. One defensible choice is the ship, because it enabled settlement and trade, while stockfish sustained northern societies through the colder centuries. The ship’s long life also shows how a useful technique can find work beyond its original purpose.

READ CHAPTER 6 — Norse stockfish trade and legacy →

For the small and vulnerable community of the first century, the lake was mostly an advantage. It offered protection, food and canoe transport, allowing numbers to grow despite scarce farmland and the absence of draught animals. The islands had no springs, however, and the closed basin brought salt and flooding. Those burdens remained manageable while the city was small and under Tepanec rule, with no large labour force at its command. After 1428, power over the shores let the Mexica enlarge the city and engineer the water. More people could benefit from the lake, but more also depended on its uncertain level.

READ CHAPTER 7 — Founding of Tenochtitlan →

The Mexica gained real control: the dike checked floods and freshened the lagoon, the two-channel aqueduct supplied drinking water, and royal granaries cushioned famine. But frost and drought still destroyed harvests in 1450–54, and the Acuecuexco flood of 1499 exposed the danger of adding water to a closed basin. Engineering also made a larger city possible, so a failure could harm more people. Historians of risk call the resulting pattern the safe-development paradox: protection encourages people and investment to concentrate, increasing the cost of a later disaster. The Mexica managed their environment more effectively than their predecessors, within limits they did not fully understand.

READ CHAPTER 8 — Aztec dikes, aqueducts and floods →

The chinampas gave the city a substantial supply close enough for fresh produce to travel by canoe. Their moisture and frost protection made harvests more reliable, and estimated maize yields were perhaps three times those of rain-fed fields. The southern zone expanded after Xochimilco and Chalco were conquered. Parsons estimated that chinampas could feed perhaps 100,000 people or more, but many estimates put the city’s population at 150,000–200,000 or higher. The difference had to be made up through exchange and tribute, including grain, beans and cotton from distant provinces. We cannot calculate exact shares while the cultivated area, population and tribute volumes remain uncertain. The city depended on several connected sources, and disruption to those connections threatened its food supply.

READ CHAPTER 9 — Aztec chinampas →

The plan served both purposes, often through the same works. Canals and streets allowed movement and drainage; the bridges, aqueduct and reuse of waste helped a dense population live on water. At the center, the sacred precinct and repeated enlargements of the Templo Mayor expressed religious and political authority, while the quarters and causeways related the city to the four directions. The connections ran deeper: rulers mobilized labor for hydraulic works, and a shrine to Tlaloc placed the rain god at the religious center. Historians still debate how much of the residential layout rulers directed and how much developed through neighborhoods. Tenochtitlan shows how environmental works can be built and maintained within political and religious institutions.

READ CHAPTER 10 — Layout of Tenochtitlan →

The island concentrated perhaps 200,000 people where canoes and causeways could supply them. Those same connections could be blocked: the besiegers cut the aqueduct, fought along the causeways and used brigantines to contest the lake. The empire that fed the city through tribute had also made enemies among subjects and surrounded rivals. Their tens of thousands of troops gave the Spaniards a coalition capable of conducting the siege. Smallpox, a shock no Mesoamerican society could have anticipated, killed leaders and defenders beforehand. Historians differ in the weight they give Indigenous politics, disease and Spanish technology. Together these forces exposed a vulnerability in a system built to manage water, frost and food.

READ CHAPTER 11 — Fall of the Aztec Empire →

We need a standard before choosing a winner. By scale and achievement, the Mexica sustained Tenochtitlan, a city of perhaps 200,000, through dikes, aqueducts, chinampas and tribute; their networks helped them survive famine and flood. Norse Greenland held at most a few thousand people and was abandoned. By duration, the comparison changes: Norse Greenland lasted about 450 years, longer than the Mexica empire's century of dominance after 1428, and Iceland still has its assembly and literature. Both traditions also left innovations in use: clinker construction, stockfish and the Althing on one side, chinampas on the other. Neither ending can be attributed to climate alone. Economic and other pressures accumulated in Greenland; a coalition and epidemic confronted Tenochtitlan. A judgment of success should therefore identify its standard and consider the time over which a system worked and the human and natural shocks it faced.

READ CHAPTER 12 — Norse and Aztecs compared →