The 20th century

How this is measured

• Placing people in time. Each person belongs to the century in which they were most active — around age 35, and never after their death.
• Who ranks highest. Within a century, people are ranked where two independent signals agree: how many of the world’s Wikipedia language editions cover them, and how many people actually read about them. Article counts alone can be lifted by a person’s own circle; readers cannot.
• Fame in print. The curves count how often a name appears in Google Books from 1800 to 2019, as a share of all the words printed each year, in the person’s own language wherever that corpus exists. Those decades are over, so each measurement is made once and kept.
• What is left out. A lifetime is measured only from 1820, when there is enough print to judge; the five years after a death are skipped as obituaries; and a name shared with someone equally notable is credited to neither.