Where the eight eras overlap, and why
The eight eras in this atlas do not form a clean partition of time. Their stated date ranges overlap - by a single year in one place, by fifty years in three places, and by about six centuries between Ancient Greece and The Roman World. That is not an error in the data. It is what periodisation is: a set of claims about which political and cultural system mattered most in a region, laid over a continuous timeline that has no joints in it.
The practical consequence for anyone using the atlas is that an era is a filing decision about a person, not a statement about a date. Twenty-nine of the 125 figures have a life that starts before, or ends after, the stated range of the era they are filed under. This guide gives every overlap and every one of those 29 cases, so you can see where the boundaries bend.
The eight ranges, side by side
Here are the eras as the atlas states them, in order, with each one's overlap with the next.
Only one pair leaves a gap: Rome's stated end, 476 CE, is 24 years before Medieval Europe's stated start. That gap is itself a convention - the deposition of the last Western emperor in 476 is the textbook marker, and the round number 500 is where the medieval period is conventionally said to begin, so the atlas inherits a 24-year no-man's-land that no figure occupies.
| Era | Stated range | Figures | Overlap with the next era |
|---|---|---|---|
| Ancient Greece | ~800-146 BCE | 14 | About 600 years with Rome (753-146 BCE) |
| The Roman World | ~753 BCE-476 CE | 16 | None - a 24-year gap to 500 CE |
| Medieval Europe | ~500-1400 CE | 15 | 50 years with the Renaissance (1350-1400) |
| The Renaissance | ~1350-1600 | 16 | The single year 1600 |
| Scientific Revolution & Enlightenment | ~1600-1800 | 16 | 50 years with the Age of Revolution (1750-1800) |
| Age of Revolution | ~1750-1850 | 14 | 50 years with the Industrial age (1800-1850) |
| Industrial & Victorian Age | ~1800-1910 | 18 | 30 years with the Modern era (1880-1910) |
| The Modern Era | ~1880-1965 | 16 | - |
The six-century overlap is the honest one
Greece and Rome overlap from 753 BCE to 146 BCE because both civilisations existed through those six centuries. Rome's range opens at 753 BCE - the traditional founding date, itself a later Roman construction - and Greece's closes at 146 BCE, the year Roman armies sacked Corinth and Greece became a Roman province. For most of that span the two are not sequential at all; they are neighbours, trading partners and eventually conqueror and conquered.
So the two era hubs are not a before and an after. They are two places to stand. Archimedes, born about 287 BCE in Syracuse, is filed under Ancient Greece - he wrote in Greek, in a Greek city - and he was killed during a Roman siege. Hannibal Barca (c. 247 to c. 183 BCE) is filed under The Roman World although he was Carthaginian and spent his life fighting Rome, because the Roman system is the frame in which his campaign is legible. Both filings are defensible. Neither is a fact about a year.
The 29 lives that spill past their era
A figure sits inside their era's range when they were born no earlier than its start and died no later than its end. Twenty-nine of the 125 do not. The breakdown by era is the most useful single table in this guide, because it shows exactly where each boundary is soft.
Two eras are completely clean: every figure in Ancient Greece and every figure in The Roman World lives inside the stated range. The Modern Era is the softest, with ten of its sixteen figures outside the range at one end or the other - which is what you would expect of the most recent era in any periodisation, because its end date is a choice about where the present begins rather than a historical marker.
| Era | Born before the start | Died after the end | Examples |
|---|---|---|---|
| Ancient Greece | 0 | 0 | - |
| The Roman World | 0 | 0 | - |
| Medieval Europe | 1 | 1 | Justinian I born 482; Joan of Arc died 1431 |
| The Renaissance | 0 | 3 | Elizabeth I 1603, Shakespeare and Cervantes 1616 |
| Scientific Revolution & Enlightenment | 3 | 2 | Francis Bacon born 1561; Thomas Jefferson died 1826 |
| Age of Revolution | 3 | 2 | George Washington born 1732; Alexander von Humboldt died 1859 |
| Industrial & Victorian Age | 0 | 4 | Nikola Tesla died 1943; Thomas Edison 1931 |
| The Modern Era | 5 | 5 | Sigmund Freud born 1856; Rosa Parks died 2005 |
Why a figure is filed where they are
In every one of those 29 cases the era records what the person did, not when they breathed. Four patterns cover almost all of them.
First, the work came late in a long life. Nikola Tesla died in 1943, thirty-three years after the Industrial & Victorian Age closes, but his alternating-current work belongs to the 1880s and 1890s. Filing him under The Modern Era would put him next to Albert Einstein and imply a twentieth-century career.
Second, the work came early in a long life. Rosa Parks died in 2005, forty years past the Modern Era's stated end, and the act she is known for happened in 1955 - squarely inside it.
Third, the figure founded the era they are too early for. Francis Bacon (born 1561), Galileo Galilei (1564) and Rene Descartes (1596) are all born before the Scientific Revolution's stated 1600 start. They are what starts it. A periodisation that begins in 1600 cannot also contain the births of the people who caused 1600 to matter.
Fourth, the figure outlived their moment into a different one. Thomas Jefferson is filed under the Enlightenment for the Declaration of Independence in 1776 and died in 1826, deep inside the Age of Revolution by date - and he is not in that era, because the revolution hub is built around the generation that fought and governed after him.
The one-year touch, and the three fifty-year seams
The Renaissance and the Enlightenment meet at exactly one year, 1600, and that single-year seam is doing more work than any other boundary in the atlas. On the Renaissance side the frame is art, patronage and the recovery of classical texts; on the Enlightenment side it is method, instrument and law. Figures born in the 1560s - Galileo, Bacon - cross it, which is why the Enlightenment hub contains three figures born before its own start date.
The three fifty-year seams - 1350-1400, 1750-1800, 1800-1850 - are different. Each one marks a period where two systems genuinely ran side by side: late-medieval institutions alongside Italian humanism; absolutist monarchy alongside revolutionary politics; agrarian economies alongside steam. Where a seam is fifty years wide, expect to find the same decade represented on two different era hubs, and expect the filing to follow the figure's subject matter.
If you want to see a seam from the inside, open the two hubs on either side of it and compare the birth years. Medieval Europe runs from Justinian I (482) to Joan of Arc (c. 1412); The Renaissance runs from Johannes Gutenberg (c. 1400) to Shakespeare (1564). Gutenberg and Joan of Arc were alive at the same time, in the same part of Europe, and they are on different hubs.
How to use the eras without being misled by them
Three habits make the era hubs more useful and less deceptive.
Use an era as a reading set, not as a date filter. If you want everyone alive in a given decade, the timeline answers that question directly and the era hubs do not.
When a figure seems misfiled, check what they are known for rather than when they lived; in this atlas the era almost always tracks the work. And when a claim turns on a boundary - the Renaissance ended in, the medieval period gave way to - treat the boundary as the convention it is. The eight ranges here are standard, widely taught and defensible. They are not measurements.
- Both eras that cover antiquity are internally clean: 30 figures, none outside their range.
- Three boundaries are fifty years wide; one is a single year; one leaves a 24-year gap.
- 29 of 125 figures fall outside their era's stated range at one end.
- The Modern Era is the softest boundary in the atlas, at ten of sixteen.
Questions readers ask
Why do Ancient Greece and The Roman World both cover the third century BCE?
Because both civilisations existed then. Rome's range starts at its traditional 753 BCE founding date and Greece's ends in 146 BCE, when Greece became a Roman province, so the two overlap for about six centuries. During that span they are neighbours and rivals rather than predecessor and successor, and a figure is filed by which system frames their work.
Is a figure's era wrong if their dates fall outside it?
No. The era records the period a figure belongs to by subject matter. Rosa Parks died in 2005, forty years after The Modern Era's stated end, and is filed there because the Montgomery bus boycott was in 1955. Twenty-nine of the 125 figures are outside their era's range at one end.
Which era boundary is the most arbitrary?
The 1600 line between the Renaissance and the Scientific Revolution, which is a single year wide and separates two frames - art and patronage on one side, method and instrument on the other - rather than two periods. Three figures on the Enlightenment hub were born before it.
Where is the gap between the eras?
Between 476 CE, where The Roman World ends, and 500 CE, where Medieval Europe begins. Both are conventional markers: the deposition of the last Western Roman emperor, and a round number. No figure in the atlas was born in those 24 years.
How do I find everyone alive in a particular century?
Use the timeline, which orders all 125 figures by birth year with century dividers. The era hubs answer a different question - which figures belong to a period - and because the ranges overlap, two hubs can both contain a given decade.
Where this comes from
Every count in this guide is derived from the atlas data itself rather than written by hand, so the prose cannot drift from the corpus. The profiles are researched editorial summaries, not primary sources: what a figure profile contains - and what it does not sets out exactly which fields exist and where they stop.