Hermaeus was the last Indo-Greek king, ruling the Paropamisadae region centered on Kabul in the 1st century BCE. His reign is generally dated from approximately 90 to 70 BCE, though some estimates extend it as late as 40 BCE. His rule concluded Greek political power in the area, as his territory was absorbed by the nomadic Yuezhi and Saka peoples.

Numismatic evidence provides the primary source for understanding his reign. His coins display a blend of Greek and Indian iconography, often featuring his portrait and the Greek epithet "Soter," meaning Savior. He may have ruled jointly with a Queen Kalliope. Hermaeus is not known as an author of any literary or historical works; consulted sources identify him exclusively as a political figure with no attested writings.

His overthrow marks the end of nearly three centuries of Hellenistic rule in Central Asia and northwestern India. His coinage is a crucial archaeological source for this final period, demonstrating significant cultural syncretism. The conquest of his territory paved the way for the rise of the Kushan Empire, which became a major center of Buddhism and a pivotal power along the Silk Road.