An invoice for a gate in the tower of the city wall of Isin demonstrates how various sorts of craftsmanship and materials went into the manufacture of a single object. City walls were monumental defensive works punctuated at intervals by towers that provided lookout posts for sentries. The presence of monumental walls around a city indicates the need for military defense and the ability of leadership to organize necessary labor and materials; the kind of organization shown by the text below is just one small example. As public architecture, walls had an aesthetic as well as a practical function; thus, the components of the wall— such as a tower gate—were the product of high-quality materials and craftsmanship. The text is dated the thirty-third year of Ishbi-Erra's reign (circa 2017 - circa 1985 B.C.E.) over...