SortStack #9 — 2026-06-18

By year · Order from earliest to most recent.

1. The Great Pyramid of Giza is completed for Pharaoh Khufu 2560 BCE

   It remained the tallest human-made structure on Earth for about 3,800 years, until Lincoln Cathedral's spire topped it in the 1300s.

2. Qin Shi Huang unifies China and declares himself its first emperor 221 BCE

   He standardized writing, currency, and axle widths — and was buried with an estimated 8,000 life-sized terracotta soldiers, no two faces alike.

3. Isaac Newton publishes the Principia, laying out his laws of motion 1687

   The Royal Society couldn't afford to print it — it had blown its budget on a lavish history of fish — so astronomer Edmond Halley paid out of his own pocket.

4. Germany invades Poland, beginning the Second World War 1939

   Britain and France declared war two days later — then months of eerie quiet followed on the Western Front, a period nicknamed the 'Phoney War.'

5. The world's first website goes online at CERN 1991

   Tim Berners-Lee's original site, info.cern.ch, explained what the web was and how to make your own page. A restored copy is still online today.

6. Dolly the sheep becomes the first cloned mammal 1996

   She was cloned from a mammary gland cell, so the scientists named her after Dolly Parton.

← All puzzles · Play today’s SortStack