King Wen (Ji family in 1076 BC) founded the Zhou dynasty after the Shang dynasty. The dynasty is known for its social hierarchy, language, length of reign and military leaders. Iron Age encouraged the dynasty’s government in centralization. Through it, the iron tools substituted the wood ones to make the agriculture labor faster and more productive. The military also benefitted from the swords and iron armors. Because of this, states also had confidence into fighting each other, provided by the new tools. This induced more wars against states and called “The Period of the Warring States”.