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.
Uruk
The Eanna district is historically significant as both writing and monumental public architecture emerge here during Uruk periods VI-IV. The combination of these two developments places Eanna as arguably the first true city and civilization in human history. Eanna during period IVa contains the earliest examples of cuneiform writing and possibly the earliest writing in history. Although some of these cuneiform tablets have been deciphered, difficulty with site excavations has obscured the purpose and sometimes even the structure of many buildings.