D. Bierens de (David Bierens) Haan

Born in Amsterdam in 1822, he studied at the Athenaeum Illustre and later at Leiden, where he earned a doctorate in 1843. He went on to spend much of his career at Leiden University, teaching mathematics and building a reputation as a careful scholar.

His name is most closely linked with the Eulerian integral and with the reference work now known as the Bierens de Haan tables, a major collection of definite integrals. He also wrote on the history of mathematics and helped document the lives and work of earlier scientists, showing the same patience for historical detail that marked his mathematical writing.

He died in 1895. Today he is remembered less as a public celebrity than as a scholar's scholar: someone whose books, tables, and historical studies quietly supported later generations of mathematicians.