That Gautam Buddha was born in Lumbini is confirmed by whose inscription?

Contemporary epigraphic evidence — inscriptions engraved on a ruler's own orders — is the most authoritative primary source for locating and dating events in ancient history. Among Mauryan-era records, the edicts and pillar inscriptions of Emperor Ashoka are extensively studied surviving royal inscriptions in the Indian subcontinent, recording his edicts and directives, many issued in the first person.

In his 20th regnal year (around 249 BCE), Ashoka personally visited Lumbini and had a pillar erected there. Its Brahmi-script inscription — the Rummindei (Lumbini) Minor Pillar Inscription — states that 'here the Buddha, the sage of the Shakyas, was born' (hida budhe jate sakyamuni), and records that Ashoka exempted the village from the bali tax and reduced its land revenue to one-eighth (bhaga) in honour of the site. This inscription is therefore the earliest and most authoritative epigraphic confirmation that the Buddha was born at Lumbini — a fact UNESCO and the Lumbini Development Trust cite today in recognising the site as a World Heritage property.

The inscriptions left by the other rulers named here are devoted to entirely different subjects:

• Samudragupta's own inscription, the Allahabad Pillar Prashasti composed by his court poet Harishena, is devoted to celebrating his military conquests and imperial titles.

• Harsha's reign is documented through Banabhatta's court biography Harshacharita and the travel account of the Chinese pilgrim Xuanzang — literary and travel narratives, not an inscription commissioned by Harsha himself.

• Pulakeshin II is remembered through the Aihole inscription (composed by Ravikirti), celebrating his own reign and his victory over Harsha.

Only the inscription Ashoka had engraved on the Lumbini pillar confirms the Buddha's birthplace, so his inscription is the answer.