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.
Valley of the Kings The Valley of the Kings (Arabic: وادي الملوك‎ ‎ "Wādī al Mulūk" ), the "Valley of the Gates of the Kings" (Arabic: وادي ابواب الملوك‎ ‎ "Wādī Abwāb al Mulūk" ), is a valley in Egypt where, for a period of nearly 500 years from the 16th to 11th century BC, rock cut tombs were excavated for the Pharaohs and powerful nobles of the New Kingdom (the Eighteenth to the Twentieth Dynasties of Ancient Egypt).