Tablets, once written, were fired in hot kilns,making them hard and durable. Collections of these clay documents made up the first archives. They were at the root of first libraries. Tens of thousands of written tablets, including many fragments, have been found in the Middle East.
In the Minoan/Mycenaean civilizations, surviving writing is mainly that used for accounting. Tablets serving as labels, with the impression of the side of a wicker basket on the back, and tablets showing yearly summaries, suggest a sophisticated accounting system.