The Bronze Age is a historical period characterized by the use of bronze, proto-writing, and other early features of urban civilization. The Bronze Age is the second principal period of the three-age Stone-Bronze-Iron system, as proposed in modern times by Christian Jürgensen Thomsen, for classifying and studying ancient societies.
An ancient civilization is defined to be in the Bronze Age either by producing bronze by smelting its own copper and alloying with tin, arsenic, or other metals, or by trading for bronze from production areas elsewhere. Bronze itself is harder and more durable than other metals available at the time, allowing Bronze Age civilizations to gain a technological advantage.
Copper-tin ores are rare, as reflected in the fact that there were no tin bronzes in Western Asia before trading in bronze began in the 3rd millennium BC. Worldwide, the Bronze Age generally followed the Neolithic period, with the Chalcolithic serving as a transition. Although the Iron Age generally followed the Bronze Age, in some areas (such as Sub-Saharan Africa), the Iron Age intruded directly on the Neolithic.
Bronze Age cultures differed in their development of the first writing. According to archaeological evidence, cultures in Mesopotamia (cuneiform script) and Egypt (hieroglyphs) developed the earliest viable writing systems.
The overall period is characterized by widespread use of bronze, though the place and time of the introduction and development of bronze technology were not universally synchronous. Human-made tin bronze technology requires set production techniques. Tin must be mined (mainly as the tin ore cassiterite) and smelted separately, then added to molten copper to make bronze alloy. The Bronze Age was a time of extensive use of metals and of developing trade networks (See Tin sources and trade in ancient times). A 2013 report suggests that the earliest tin-alloy bronze dates to the mid-5th millennium BC in a Vinča culture site in Pločnik (Serbia), although the civilization is not conventionally considered part of the Bronze Age. The dating of the foil has been disputed.