Bronze Age
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 this culture is not conventionally considered part of the Bronze Age. The dating of the foil has been disputed.
Threshing board
The threshing boards must have been important in the protohistory of Mesopotamia, since they already appear in some of the oldest written documents discovered: specifically, several sandstone tablets from the early town of Kish (Iraq), engraved with cuneiform pictograms, which could be the world's oldest surviving written record, dating to the middle of the 4th millennium BC (Early Uruk period). One of these tablets, preserved in the Ashmolean Museum of Oxford University, appears to have pictures of threshing boards on both faces, next to some numeric symbols and other pictograms. These presumed threshing boards (which might instead be sledges) have a shape similar to threshing carts that were used until recently in parts of the Middle East where non-industrial agriculture survived. Descriptions also appear in numerous cuneiform clay tablets as early as the third millennium BC.