Archaeologists have discovered the large limestone burial chamber of an unidentified ancient Egyptian pharaoh near the city of Abydos dating to about 3,600 years ago during a chaotic period in Egypt's history.

An international team of archeologists have discovered a massive tomb that belonged to one of ancient Egypt ’s earliest pharaohs. However, the ruler’s identity remains a mystery—as do many details of his long-lost dynasty.

The burial chamber most likely belonged to a ruler in a line of kings once lost to history, researchers said. “It’s a new chapter in investigating this dynasty,” one noted.