The ambiguity of the signs was a characteristic of cuneiform and remained so until it finally died out. It represents one of the major difficulties in dealing with this script ... .
Hans J. Nissen, Frühe Schrift und Techniken der Wirtschaftsverwaltung im alten Vorderen Orient, 1991
The proto-cuneiform script of the Sumerians, one of humanity’s earliest scripts, emerged in the late fourth century BCE as high culture developed in Mesopotamia. Arising out of counting marks and pictograms, it was first used in the course of temple and palace management as a means of accounting and inventory, particularly for commercial purposes. The influence of numerous civilisations – Babylonians, Aramaeans, Akkadians, Assyrians, Persians and others – saw the Sumerians’ pictorial script evolving into a system of abstract cuneiform.
To adapt to various languages, the original principle of logographic script developed into syllabic writing. Because each cuneiform could represent multiple concepts, words or sounds, supplementary marks were added to aid interpretation. Reeds, cut lengthways, were pressed into soft clay to leave tapered marks, replacing the old technique of incised lines; this rationalised script technology and later evolved into notation in stone and other materials. Over the centuries the direction of writing changed from vertical to horizontal (left-to-right). Rich in variation, cuneiform remained in use in the Near East as a commercial, correspondence and literary script until the first century CE, when it was replaced by single-sound scripts. Georg Friedrich Grotefend was instrumental in deciphering the old cuneiform system.