More than 3,000 years ago, a long sword emblazoned with the insignia of Ancient Egypt’s Ramses II — the most powerful pharaoh of the era — was set down in a mud hut somewhere in the Nile Delta.

       A team of archaeologists digging up an ancient fort in the area spotted it and cleaned it, finding a shimmering bronze blade with the intricacies of an ornamental cartouche — the personal emblem used by the pharaohs — still visible. It had not lost its reflective shine under the layers of rust and grime accumulated over millennia.