Why is Ashoka's pillar at Lumbini historically important?

Ashoka's pillar at Lumbini is historically significant because it contains an inscription recording a visit by the Mauryan emperor Ashoka to the site he identified as the birthplace of the Buddha.1

This discovery provides critical evidence that the legend of Lumbini as the Buddha's birthplace was established as early as the 3rd century BCE. Like his other rock edicts and pillars, this monument serves as a lasting historical record of Ashoka’s devotion to Buddhism and his efforts to promote his ideology of dharma across his empire. Today, the site is recognized as a UNESCO World Heritage site and remains a major destination for pilgrimage.123