Technology & Infrastructure in the 3rd century

12 sourced entries, 202 CE to 282 CE, oldest first. Also see Technology & Infrastructure across every century or everything else in the 3rd century.

• 202Rome is a city of about 1.5 million citizens, its people housed mostly in 46,600 insulae or apartment blocks, each three to eight stories high, flimsily made of wood, brick or rubble.source
• 211Baths of Caracalla construction begins (approximate date).source
• 212Construction begins on the Baths of Caracalla in Rome.source
• 217Macrinus, of Mauretania, becomes the first equestrian Roman emperor.source
• 234Emperor Alexander Severus and his mother Julia Mamaea move to Moguntiacum (modern Mainz), the capital of Germania Superior. His generals have planned a military offensive and built a bridge across the Rhine. Alexander prefers to negotiate for peace by buying off the Alemanni. This policy outrages the Roman legions and he loses the trust of the troops.source
• 250The Igel Column is erected at Trier in Germany.source
• 250Teotihuacán is rebuilt as a four-quartered cosmogram by Zapotec architects brought from Monte Albán in Oaxaca.source
• 250The earliest Chinese references to a device known as "emperor's south-pointing carriage" date to this period.source
• 260King Shapur I sends Valerian to Bishapur and uses the captured Roman army for engineering plans. They construct the Band-e Kaisar ("Bridge of Valerian").source
• 271Aurelian begins construction of a new defensive wall to protect Rome. The Aurelian Walls, 19 km mi, enclose the city with fortifications.source
• 274Japanese shipwrights build a 100-foot oar-powered vessel for Emperor Ōjin. The Japanese will not use sails for another seven centuries.source
• 282A new city is constructed in Fuzhou, slightly south of the original city Ye (the main street of the city has remained unchanged since that time).source