The written language of Mesopotamia was Sumerian, recorded in a script called cuneiform, which first appeared around 3100 BCE in the city of Uruk (in modern-day Iraq). Over the following three thousand years, cuneiform was adapted to write several additional languages, most importantly Akkadian and its dialects, Babylonian and Assyrian. The script itself, rather than any single language, was the thread connecting Mesopotamian civilization from its earliest accounting records to its final astronomical texts.
How Cuneiform Began in Uruk
Writing in Mesopotamia did not start as literature or storytelling. It started as bookkeeping. The city of Uruk, the largest urban center in southern Mesopotamia by the late fourth millennium BCE, was dominated by large temple estates that needed to track incoming grain, livestock, and fish. As the city’s population grew and diversified, temple administrators needed something more permanent than memory, so they began pressing simple pictures into small clay tablets. The earliest signs depicted exactly what was being counted: stalks of grain, fish, different types of animals.
These earliest tablets, dating to roughly 3100 BCE, are written in what scholars call proto-cuneiform. The language behind them is almost certainly Sumerian, a language unlike any other known language family. Sumerian is classified as a language isolate, meaning linguists have never been able to link it to any relative, living or dead. The people who invented writing spoke a language that, as far as we can tell, stood entirely alone.
From Pictures to Wedges
The physical process of writing shaped the script’s evolution. Mesopotamian scribes wrote on tablets of moist clay using a stylus cut from giant reed, a plant that grew abundantly along the region’s rivers and canals. Early scribes drew curved lines to sketch pictures, but they quickly discovered that pressing the reed’s angular tip into the clay was faster and more consistent. Each press left a small wedge-shaped mark, and the entire script came to be built from combinations of three basic wedge types: vertical, horizontal, and oblique. The Latin word for “wedge” is cuneus, which is where the name cuneiform comes from.
A skilled scribe could produce each wedge with a single impression, varying the stylus’s angle and pressure to control the mark’s direction and length. The reed left a distinctive signature: one smooth, slightly curved face and one flat face that sometimes showed the plant’s fibrous texture. Over centuries, the original pictographic signs became increasingly abstract, eventually bearing little resemblance to the objects they once depicted. A sign that started as a drawing of a head became a compact cluster of wedges that simply meant “head” by convention.
Sumerian: The First Written Language
Sumerian was the dominant written language of southern Mesopotamia for more than a thousand years, from roughly 3100 BCE through the end of the third millennium BCE. It served as the language of temple records, royal inscriptions, hymns, proverbs, and some of the world’s oldest known literary works. Even after Sumerian stopped being spoken as an everyday language (sometime around 2000 BCE), it persisted for centuries as a language of scholarship and religion, much like Latin in medieval Europe. Scribes continued to study Sumerian grammar and copy Sumerian texts well into the first millennium BCE.
Akkadian and Its Two Major Dialects
By the middle of the third millennium BCE, cuneiform was adapted to write Akkadian, an entirely different language. Where Sumerian was a language isolate, Akkadian belonged to the East Semitic branch of the Semitic language family, making it a distant relative of Arabic and Hebrew. The two languages are fundamentally different in their word structure, and borrowings between them were mostly limited to nouns and some adjectives rather than core grammar.
Akkadian gradually became the primary spoken and written language across Mesopotamia. It split into two major regional dialects: Babylonian in the south and Assyrian in the north. These dialects differed in pronunciation, grammar, and some vocabulary, and scribes were well aware of the distinctions. Assyrian scholars writing to their king often elevated their prose by switching into Standard Babylonian, which functioned as a prestige literary dialect. Some scribes even practiced deliberate variation in how they spelled the same word, alternating between syllabic writing and older Sumerian-derived symbols from one line to the next to avoid repetition.
Akkadian was the language of government, diplomacy, and law. The Code of Hammurabi, one of the most famous legal documents in history, was carved onto a basalt stele in Akkadian around 1792 to 1750 BCE, during the reign of King Hammurabi of Babylon. Akkadian also served as a lingua franca across the ancient Near East. Letters between Egyptian pharaohs and their counterparts in Mesopotamia, Anatolia, and the Levant were written in Akkadian cuneiform.
Other Languages Written in Cuneiform
Cuneiform proved remarkably adaptable. Over its long history, the script was borrowed and modified to write languages well beyond Mesopotamia’s borders. Elamite (spoken in what is now southwestern Iran), Hittite (an Indo-European language of ancient Anatolia), Hurrian (spoken across northern Mesopotamia and Syria), and Old Persian all used versions of cuneiform. Each culture adjusted the sign system to fit its own language’s sounds and structure, sometimes simplifying the script dramatically. Old Persian cuneiform, for instance, reduced the system to a semi-alphabetic set of around 36 signs, a far cry from the hundreds used in Babylonian.
The Slow Decline of Cuneiform
Cuneiform’s dominance began eroding around the eighth century BCE as Aramaic, written in a simple 22-letter alphabet, spread across the region. Aramaic had a practical advantage: its alphabet was far easier to learn than a cuneiform system requiring mastery of hundreds of signs. Aramaic could also be written with ink on lightweight materials like leather and papyrus, rather than pressed into heavy clay tablets. As the Assyrian and later Persian empires incorporated vast, multilingual populations, Aramaic became the common administrative language.
Cuneiform did not vanish overnight. It remained in use for specialized purposes, particularly astronomy, mathematics, and religious texts, in Babylonian temple communities. The last known cuneiform tablet that carries a date corresponds to 75 CE, though the script likely lingered in some form for another century or two after that. By then, the knowledge of how to read cuneiform had effectively died out, and the tablets lay buried and unreadable for nearly two millennia.
How Cuneiform Was Redeciphered
The key to unlocking cuneiform came from a massive rock carving on a cliff face at Behistun, in western Iran. Carved around 520 BCE on the orders of the Persian king Darius I, the inscription tells the story of his rise to power in three languages: Old Persian, Elamite, and Babylonian. All three were written in different versions of cuneiform. Because scholars in the nineteenth century were able to make progress on Old Persian first (it had the simplest sign system), they could use the Behistun Inscription as a decoder for the other two scripts, much as the Rosetta Stone had opened Egyptian hieroglyphics. Once Babylonian cuneiform was cracked, the entire literary and administrative archive of Mesopotamia became readable for the first time in roughly two thousand years.