LONDON — The sound of unbridled joy seldom breaks the quiet of the British Museum’s great Arched Room, which holds its collection of 130,000 Assyrian cuneiform tablets, dating back 5,000 years.

But Michael Jursa, a visiting professor from Vienna, let out such a cry last Thursday. He had made what has been called the most important find in biblical archaeology for 100 years, a discovery that supports the view that the historical books of the Bible are based on fact.

Searching for Babylonian financial accounts among the tablets, Jursa suddenly came across a name that he half remembered — Nabusharrussu-ukin, described there in 2,500-year-old writing as “the chief eunuch” of Nebuchadnezzar II, king of Babylon.

Mr. Jursa, an Assyriologist, checked Chapter 39 of the Book of Jeremiah, and he found, spelled differently, the same name — Nebo-Sarsekim. Nebo-Sarsekim, according to Jeremiah, was Nebuchadnezzar II’s “chief officer” and was with him at the siege of Jerusalem in the year 587 before the common era, when the Babylonians overran the city.

The small tablet, the size of “a packet of 10 cigarettes” according to Irving Finkel, a British Museum expert, is a bill of receipt acknowledging Nabu-sharrussuukin’s payment of 0.75 kg of gold to a temple in Babylon.

The tablet is dated to the 10th year of the reign of Nebuchadnezzar II, 595 B.C.E., 12 years before the siege of Jerusalem.

Evidence from non-biblical sources of people named in the Bible is not unknown, but Nabusharrussu-ukin would have been a relatively insignificant figure. “This is a fantastic discovery, a world-class find,” Mr. Finkel said yesterday. “If Nebo-Sarsekim existed, which other lesser figures in the Old Testament existed? A throwaway detail in the Old Testament turns out to be accurate and true. I think that it means that the whole of the narrative [of Jeremiah] takes on a new kind of power.”