Epidemic in the context of "Famine"

The fall of the Western Roman Empire, also called the fall of the Roman Empire or the fall of Rome, was the loss of central political control in the Western Roman Empire, a process in which the Empire failed to enforce its rule, and its vast territory was divided among several successor polities. The Roman Empire lost the strengths that had allowed it to exercise effective control over its Western provinces; modern historians posit factors including the effectiveness and numbers of the army, the health and numbers of the Roman population, the strength of the economy, the competence of the emperors, the internal struggles for power, the religious changes of the period, and the efficiency of the civil administration. Increasing pressure from invading peoples outside Roman culture also contributed greatly to the collapse. Climatic changes and both endemic and epidemic disease drove many of these immediate factors. The reasons for the collapse are major subjects of the historiography of the ancient world and they inform much modern discourse on state failure.

In 376, a large migration of Goths and other non-Roman people, fleeing from the Huns, entered the Empire. Roman forces were unable to exterminate, expel or subjugate them (as was their normal practice). In 395, after winning two destructive civil wars, Theodosius I died. He left a collapsing field army, and the Empire divided between the warring ministers of his two incapable sons. Goths and other non-Romans became a force that could challenge either part of the Empire. Further barbarian groups crossed the Rhine and other frontiers. The armed forces of the Western Empire became few and ineffective, and despite brief recoveries under able leaders, central rule was never again effectively consolidated.

Human geography, also known as anthropogeography, is a branch of geography that studies how people interact with places. It focuses on the spatial relationships between human communities, cultures, economies, people, lifestyle and their environments. Examples include patterns like urban sprawl and urban redevelopment. It looks at how social interactions connect with the environment using both qualitative (descriptive) and quantitative (numerical) methods. This multidisciplinary field draws from sociology, anthropology, economics, and environmental science, helping build a more complete understanding of how human activity shapes the spaces we live in.

The Plague of Athens (Ancient Greek: Λοιμὸς τῶν Ἀθηνῶν, Loimos tôn Athênôn) was an epidemic that devastated the city-state of Athens in ancient Greece during the second year (430 BC) of the Peloponnesian War when an Athenian victory still seemed within reach. The plague killed an estimated 75,000 to 100,000 people, around 25% of the population, and is believed to have entered Athens through Piraeus, the city's port and sole source of food and supplies. Thucydides, an Athenian survivor, wrote that much of the eastern Mediterranean also saw an outbreak of the disease, albeit with less impact.

The war, along with the plague, had lasting effects on Athenian society. Short-term, there was civil disorder, and violations of usual funerary practices. Thucydides describes a decrease in traditional religious practices and increase in superstitious explanations. He estimates that it took 15 years for the Athenian population to recover. Long-term, the high death toll drastically redistributed wealth within Athenian society, and weakened Athens politically.

In epidemiology, an infection is said to be endemic in a specific population or populated place when that infection is constantly present, or maintained at a baseline level, without extra infections being brought into the group as a result of travel or similar means. The term describes the distribution of an infectious disease among a group of people or animals or within a populated area. An endemic disease always has a steady, predictable number of people or animals getting sick, but that number can be high (hyperendemic) or low (hypoendemic), and the disease can be severe or mild. Also, a disease that is usually endemic can become epidemic.

For example, chickenpox is endemic in the United Kingdom, but malaria is not. Every year, there are a few cases of malaria reported in the UK, but these do not lead to sustained transmission in the population due to the lack of a suitable vector (mosquitoes of the genus Anopheles). Consequently, there is no constant baseline level of malaria infection in the UK, and the disease is not endemic. However, the number of people who get chickenpox in the UK varies little from year to year, so chickenpox is considered endemic in the UK.

This list of wars by death toll includes all deaths directly or indirectly caused by the deadliest wars in history. These numbers encompass the deaths of military personnel resulting directly from battles or other wartime actions, as well as wartime or war-related civilian deaths, often caused by war-induced epidemics, famines, or genocides. Due to incomplete records, the destruction of evidence, differing counting methods, and various other factors, the death tolls of wars are often uncertain and highly debated. For this reason, the death tolls in this article typically provide a range of estimates.

Compiling such a list is further complicated by the challenge of defining a war. Not every violent conflict constitutes a war; for instance, mass killings and genocides occurring outside of wartime are excluded, as they are not necessarily wars in themselves. This list broadly defines war as an extended conflict between two or more armed political groups. Consequently, it excludes mass death events, such as human sacrifices, ethnic cleansing operations, and acts of state terrorism or political repression during peacetime or in contexts unrelated to war.
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Human life expectancy is a statistical measure of the estimate of the average remaining years of life at a given age. The most commonly used measure is life expectancy at birth (LEB, or in demographic notation e₀, where e_x denotes the average life remaining at age x). This can be defined in two ways. Cohort LEB is the mean length of life of a birth cohort (in this case, all individuals born in a given year) and can be computed only for cohorts born so long ago that all their members have died. Period LEB is the mean length of life of a hypothetical cohort assumed to be exposed, from birth through death, to the mortality rates observed at a given year. National LEB figures reported by national agencies and international organizations for human populations are estimates of period LEB.

Human remains from the early Bronze Age indicate an LEB of 24. In 2019, world LEB was 73.3. A combination of high infant mortality and deaths in young adulthood from accidents, epidemics, plagues, wars, and childbirth, before modern medicine was widely available, significantly lowers LEB. For example, a society with a LEB of 40 would have relatively few people dying at exactly 40: most will die before 30 or after 55. In populations with high infant mortality rates, LEB is highly sensitive to the rate of death in the first few years of life. Because of this sensitivity, LEB can be grossly misinterpreted, leading to the belief that a population with a low LEB would have a small proportion of older people. A different measure, such as life expectancy at age 5 (e₅), can be used to exclude the effect of infant mortality to provide a simple measure of overall mortality rates other than in early childhood. For instance, in a society with a life expectancy of 30, it may nevertheless be common to have a 40-year remaining timespan at age 5 (but not a 60-year one).