Daily History Challenge · No. 35 · Sunday 2 August 2026 · Gauntlet
Puzzle No. 35: Gauntlet
The Sunday Gauntlet: three before or after calls, four events to order and a final When? on Euclid compiles the Elements at Alexandria.
Act 1: Chain, against Copernicus publishes De revolutionibus and the heliocentric universe (1543 CE)
Before Copernicus publishes De revolutionibus and the heliocentric universe
Before Copernicus publishes De revolutionibus and the heliocentric universe
After Copernicus publishes De revolutionibus and the heliocentric universe
Act 2: Order, earliest first
Act 3: When?
Around 300 BCE, working in Alexandria under the early Ptolemies, the mathematician Euclid composed the Elements, a treatise in thirteen books that organised the geometry and number theory of the Greek world into a single deductive system. Beginning from a small set of definitions, postulates and common notions, Euclid derived hundreds of theorems through rigorous logical proof, covering plane and solid geometry, ratio and proportion, and the theory of numbers including a proof of the infinitude of primes. The work synthesised earlier mathematics from Pythagoras, Eudoxus, Theaetetus and others into a clear, comprehensive whole. The Elements became the most influential mathematical text ever written and the world's longest-used textbook, shaping the teaching of geometry and the very idea of axiomatic proof for more than two thousand years. It stands as the foremost monument of Hellenistic science and of Alexandria's role as the intellectual capital of the age.