While others had made attempts, Rawlinson was the first to make significant progress. In the 1840s, he studied the Behistun Inscription, a multilingual text carved into a cliff face in Persia. He was able to decipher the Persian, Elamite, and Babylonian sections of the inscription, leading to the understanding of cuneiform writing.
However, it's important to note that Rawlinson built upon the work of earlier scholars like George Grote, who had recognized some of the cuneiform signs, and François Lenormant, who had identified a few words.