How long was the rule of the dynasty that was active when the Rosetta Stone was inscribed?
Ptolemaic dynasty The Ptolemaic dynasty (Ancient Greek: Πτολεμαῖοι , "Ptolemaioi"), sometimes also known as the Lagids or Lagidae (Ancient Greek: Λαγίδαι , "Lagidai", after Lagus, Ptolemy I's father), was a Macedonian Greek royal family, which ruled the Ptolemaic Kingdom in Egypt during the Hellenistic period. Their rule lasted for 275 years, from 305 to 30 BC. They were the last dynasty of ancient Egypt.
Great Karnak Inscription The Great Karnak Inscription is an ancient Egyptian hieroglyphic inscription belonging to the 19th dynasty Pharaoh Merneptah. A long epigraph, it was discovered at Karnak in 1828-29. According to Wilhelm Max Müller, it is "one of the famous standard texts of Egyptology... [and has been] ... one of the greatest desiderata of scholars for many years."