Dashed left edge = started before this timeline ·
Dashed right edge = still ongoing
Events in 246 BC 2
285 BC – 246 BCLibrary of Alexandria -- all human knowledgeThe Library of Alexandria, developed under Ptolemy II Philadelphus (285-246 BC), holds between 400,000 and 700,000 scrolls. Its scholars produce the first critical editions of Homer, develop geometry (Euclid), measure the Earth's circumference (Eratosthenes), catalogue the stars (Hipparchus) and lay the foundations of ancient science. It is the greatest intellectual institution of the ancient world.
246 BC – 208 BCConstruction of the Great Wall beginsLinking earlier walls into a unified northern defenceQin Shi Huang ordered the linking and extension of existing northern walls into a continuous defensive barrier against Xiongnu nomads. Hundreds of thousands of workers — soldiers, peasants and convicts — built the wall under brutal conditions. This early wall was largely of earth and wood; the iconic stone wall seen today was built by the Ming dynasty. The wall represents the most ambitious construction project of the ancient world.