How did Thomas Young use the cartouches on the Rosetta Stone to identify Ptolemy’s name?

Thomas Young utilized the cartouches—oval figures enclosing hieroglyphs—found on the Rosetta Stone to advance the decipherment of hieroglyphic writing.

Contrary to the long-held assumption that hieroglyphs were purely symbolic, Young proved that the signs within these cartouches represented proper names, specifically identifying the name of Ptolemy V Epiphanes. By comparing the Greek text on the stone with the Egyptian inscriptions, he was able to isolate these royal names. Furthermore, Young determined the direction in which the script should be read by observing the orientation of the bird and animal characters within the inscriptions. While his work provided a crucial foundation by isolating single-consonant signs and confirming that cartouches contained royal names, he did not fully decipher the script; that achievement was later expanded upon by Jean-François Champollion.12