
Canals: c. 515 BCE - 1903

Celts: c. from 1750 BCE - c. 780

Commerce and industry: c. 3000 BCE - 2011

Exploration: c. 600 BCE - 1958

Migration: c. 2.2 million years ago - 1948

Seven Wonders of the World: c. 2500 BCE - c. 120 BCE

Slavery: c. 3000 BCE - 1888

Social and domestic: c. 15,000 years ago - 2011

Society: c. 2.2 million years ago - 2011
