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.

It also carries an inscription by Tomomitsu. Another highlight is a “kodachi” short sword forged by Rai Kunitoshi, a representative swordsmith of the Rai school in Yamashiro province (present ...