History terms in Climate and innovation

The dike about 16 km long built across Lake Texcoco after the flood of 1449, which protected Tenochtitlan from floods and separated salty eastern water from the fresher lagoon around the city.

The basic political unit of central Mexico: a city-state made up of a town, its villages and lands, with its own ruler, temple and patron god.

The national assembly of Iceland, founded in 930, which met each summer at Thingvellir to make law and settle disputes; it adopted Christianity in 999 or 1000.

The incorporation of a territory into a state or empire. In the Aztec Empire it usually meant assigning a conquered region to a tribute province while its own rulers stayed in place.

Land that can be ploughed and used to grow crops; in the Norse North Atlantic, meadow and pasture for hay mattered as much as fields.

Iron ore that forms in bogs and wetlands, which the Norse smelted in small furnaces to make iron, as at L'Anse aux Meadows.

A free farmer in Norse society: the head of a household who owned or rented land, could bear arms and had the right to speak at the thing.

A cowshed; in Norse Greenland, cattle were kept in turf-walled byres for up to seven months and fed on stored hay.

A temple school, mainly for the sons of nobles, that trained priests, judges and officials in religion, history, the calendar and the reading of painted books.

A Mexica steward placed in a conquered town to collect tribute and send it to the capitals of the Triple Alliance.

A ward or neighbourhood of an Aztec town that held land in common and had its own temple, school and military unit.

A raised road built across water or marsh. Tenochtitlan was joined to the shore by causeways with removable bridges, which also acted as dikes.

A raised field built from layers of mud and vegetation in a shallow freshwater lake and surrounded by canals, which allowed intensive farming with several harvests a year.

The second office in the Mexica state after the tlatoani, responsible for justice, finance and the city's internal affairs. Tlacaelel held it under Itzcoatl and Moctezuma I.

A way of building a wooden hull from overlapping planks riveted together along their edges, starting from the keel, which gives a light, strong and flexible ship.

A hand-made book. In Mesoamerican history it means the painted books of the Aztecs, Mixtecs and Maya and the illustrated manuscripts made by Indigenous painters after the Spanish conquest.

A pictorial manuscript made in Mexico City about twenty years after the Spanish conquest for the viceroy Antonio de Mendoza, recording the Mexica rulers and their conquests, the tribute of each province and daily life, with Spanish notes.

The name given by the historian Robert Barlow in 1945 to a lost Nahuatl history of Tenochtitlan that both Diego Durán and Hernando Alvarado Tezozomoc used as their main source.

The dating and study of tree rings. Because a tree adds one ring a year, wider in good years and narrower in poor ones, ring patterns date wood exactly and give a record of past climate.

An Arctic people who lived in parts of Arctic Canada and Greenland before the Thule; the ruins the Norse found in Greenland may have been theirs or those of even earlier cultures.

Sea ice that moves with currents and winds; ice from the Arctic drifts down Greenland's east coast and around Cape Farewell, and when heavy it blocks shipping.

Elite Aztec military orders whose members had taken several captives in battle and wore distinctive costumes and enjoyed noble privileges.

The larger of the two Norse settlement districts in Greenland, around Eiriksfjord near the southern tip of the island, founded about 985 and abandoned by about 1450.

A drainage basin with no outlet to the sea, where water leaves only by evaporation or seepage, so that salts collect in its lowest lake.

The view that the natural environment (climate, geography, resources) decides how societies develop; most historians reject strong versions of it.

The famine in the Basin of Mexico that followed frosts and drought from about 1450 and was worst in the year One Rabbit (1454). It is one of the most widely recorded disasters in the annals before the Spanish conquest.

The twelve-book encyclopedia of Nahua life and history in Nahuatl and Spanish, compiled by the friar Bernardino de Sahagún with Nahua scholars and completed in 1577.

A pre-arranged, limited war between the Triple Alliance and cities such as Tlaxcala and Huexotzinco, fought to take captives and display courage rather than to conquer. Its purpose is debated by historians.

A system in which leaders gave land, food, protection and gifts to followers in return for loyalty and support, binding them together through obligations.

A chieftain in medieval Iceland who led religious rites and represented his followers at assemblies; Iceland had about three dozen.

An empire that controls its subjects indirectly, leaving local rulers in place and relying on tribute and the threat of force rather than occupation and direct government.

"Great speaker": the title of the ruler of Tenochtitlan as leader of the Triple Alliance.

The patron god of the Mexica, a god of war and the sun, worshipped in one of the two shrines on the Templo Mayor.

The ritual killing of people as an offering to gods. In Mexica belief it repaid the gods for creating the world and kept the sun moving; it was practised across Mesoamerica.

A long cylinder of ice drilled from an ice sheet, whose layers preserve chemical evidence of past temperatures and volcanic eruptions.

The enclosed, manured land next to a Norse farmhouse, kept for growing hay to feed animals through the winter.

A new technology, technique, institution or practice that people actually adopt and use, as distinct from an idea that is only thought of.

The Book of the Icelanders, a short history of Iceland written by the priest Ari Thorgilsson in about 1122–1133; it contains the earliest account of Erik the Red's settlement of Greenland.

The strong timber running along the bottom of a ship's hull, which gives it strength and keeps it on course under sail.

A deep, broad Norse ocean-going cargo ship that relied mainly on its sail and needed a small crew; it carried settlers, livestock and goods across the North Atlantic.

Old Norse for "land-taking": the first settlement of an empty land, used especially for the settlement of Iceland between about 870 and 930.

The Book of Settlements, a record compiled in Iceland in the twelfth and thirteenth centuries of the first settlers of Iceland, their families and their land, with some information on Greenland.

A method of navigation in which sailors judge their latitude from the height of the sun or the Pole Star, reach the latitude of their destination and then sail due east or west along it.

A long, narrow Norse warship powered by many oars and a sail, carrying a large crew for raiding and war.

An Aztec commoner. Commoners held land through their calpulli, paid tribute in goods and labour and served as soldiers.

Landless labourers who worked the private estates of Aztec nobles in return for a plot of land, a group that grew as nobles received conquered lands.

A period of about 950–1250 when the North Atlantic and many other regions were warmer than in the centuries before and after, with large regional differences in rainfall; scientists now often call it the Medieval Climate Anomaly because the change was uneven.

The cultural region of central and southern Mexico and northern Central America whose peoples, including the Olmecs, Maya and Aztecs, shared farming, calendars, writing and religious practices before the Spanish conquest.

An agricultural terrace on a hillside in central Mexico, often edged with maguey plants, that held soil and water and reduced erosion.

The Nahuatl-speaking people of Tenochtitlan and its twin city Tlatelolco, the leading partner in the Aztec Empire. "Aztec" is a later label; the Mexica used this name for themselves.

A Mesoamerican field in which maize, beans and squash are grown together, the beans enriching the soil and the squash suppressing weeds.

The language of the Mexica and many other peoples of central Mexico, still spoken by more than 1.5 million people in Mexico (2020 census). Nahua is the name for the peoples who speak it.

The medieval Scandinavian peoples of Norway, Denmark and Sweden and the communities they founded overseas, such as Iceland and Greenland, who spoke Old Norse.

A pattern of changing air pressure between Iceland and the Azores that affects the strength of westerly winds and the weather of the North Atlantic and Europe.

The first year of the 52-year Mexica calendar cycle; 1454 was a One Rabbit year. After the famine of that year, One Rabbit years were feared as times of disaster.

The most serious punishment in Norse law, removing the protection of the law from a person: lesser outlawry meant three years' exile, full outlawry meant anyone could kill the outlaw without penalty.

A member of the Aztec hereditary nobility. Nobles held offices, priesthoods and, after 1428, estates on conquered land, and paid no tribute.

The professional long-distance merchants of the Aztec world, organised in guilds, who traded beyond the empire and sometimes served as spies.

Natural records such as ice cores, tree rings, pollen and sediments that preserve evidence of past climate where there are no instrument readings.

A scientific method that estimates when a once-living thing died by measuring the decay of carbon-14 in it; a known spike in carbon-14 in tree rings can give an exact year.

A prose narrative written in medieval Iceland, mostly in the thirteenth and fourteenth centuries, about the kings of Norway or early Icelanders and their families, drawing on oral tradition.

A hut on an outlying summer pasture, used while animals grazed away from the home farm so that the meadows near the house could grow hay.

The Old Norse name for the Indigenous peoples of Greenland and North America met by the Norse; its original meaning is uncertain and it was not a name these peoples used for themselves.

Five eleventh-century ships sunk to block a channel in Roskilde Fjord, Denmark, and raised in 1962; they include an ocean-going knarr built in western Norway in about 1030.

A soured, strained milk product made in Norse Iceland and Greenland, which could be stored through the winter.

Measuring the ratios of carbon and nitrogen isotopes in bone to work out what kinds of food, for example marine or land-based, a person ate.

A law that limits what people of different ranks may wear, eat, own or build, so that each person's status is visible.

A possible Norse navigation instrument: a disc on which the shadow of a pointer showed direction. A broken wooden disc found at Uunartoq in Greenland in 1948 may be one, but this is debated.

"House of youth": the school of each calpulli where commoner boys were trained for war and public labour.

The great twin temple of Huitzilopochtli and Tlaloc at the centre of Tenochtitlan, rebuilt and enlarged in at least seven main stages and excavated since 1978.

An assembly of free men in Norse society that met at fixed times to settle disputes and make laws.

An enslaved person in Norse society, often captured in raids abroad, with no legal rights.

The ancestors of the modern Inuit, who spread east across Arctic Canada and reached northern Greenland in the thirteenth century.

"Hot land": the warm, frost-free lowlands of Mexico, such as the Gulf coast and Morelos, which produced cotton, cacao and tropical crops that the cool highlands could not.

An Aztec slave, usually a person sold or self-sold for debt or as a punishment. Slaves could own property and their children were born free.

The Mesoamerican god of rain and agriculture, worshipped in one of the two shrines on the Templo Mayor of Tenochtitlan.

The ruler of an altepetl, literally "speaker". A tlatoani was chosen from the royal family by a council of nobles.

A regular payment of goods, labour or services by a subject people to a ruler or state in recognition of its authority.

The alliance of Tenochtitlan, Texcoco and Tlacopan formed in 1428 after the defeat of Azcapotzalco, which ruled the Aztec Empire and shared its tribute.

A rack on which the skulls of sacrificed people were displayed. The great tzompantli of Tenochtitlan has been partly excavated since 2015.

In the original sense, a Scandinavian who went on a raiding or trading expedition by sea; now often used loosely for all Scandinavians of the Viking Age, most of whom were farmers.

The period of Scandinavian raiding, trade and settlement overseas, usually dated from the raid on Lindisfarne in 793 to about 1066.

The smaller, more northerly Norse settlement district in Greenland, in the fjords near modern Nuuk, founded about 985 and abandoned by about 1360.

"Binding of the years": the 52-year cycle of the Mesoamerican calendar, after which each year name recurred.