Related Clues:

• It began about 1000 B.C.
• Advanced toolmaking period
• Early period
• Early period of civilization
• Early toolmaking period
• Early tool-making time
• When bronze was replaced, historically
• It began about 3500 BC
• It started around 1100 B.C.
• It began in Europe around 1200 B.C.
• Historic toolmaking period
• Sumer's era
• When forging started
• When metal-casting started
• Period in human history