The Guardian reports that

a team led by [Robin] Coningham, a professor of archaeology and pro-vice-chancellor at Durham University, had made a startling discovery about the date of the Buddha's birth, one that could rewrite the history of Buddhism. After a three-year dig on the site of the Maya Devi temple at Lumbini in Nepal, Coningham and his team of 40 archaeologists discovered a tree shrine that predates all known Buddhist sites by at least 300 years.

The impact of Coningham's work is groundbreaking in many ways. Prior to this discovery, it had been thought that the shrine at Lumbini – an important pilgrimage site for half a billion Buddhists worldwide – marked the birthplace of the Buddha in the third century BC. But the timber structure revealed by archaeologists was radio-carbon-dated to the sixth century BC.

"It has real significance," says Coningham, 47. "What we have for the first time is something that puts a date on the beginning of the cult of Buddhism. That gives us a really clear social and economic context… It was a time of huge transition where traditional societies were being rocked by the emergence of cities, kings, coins and an emerging middle class. It was precisely at that time that Buddha was preaching renunciation – that wealth and belongings are not everything."

This last paragraph is a reference to Karl Jasper's Axial Age thesis, which you should look up.

The article also has some nice accounts of what it's like conducting archaeological fieldwork in Nepal in January and February (spoiler alert: it gets cold).