Wilhelm Seibert (1840-1925) and Heinrich Seibert (1842-1907)

Wilhelm and Heinrich Seibert both worked for Carl Kellner, the German mechanic and self-taught mathematician who founded the company that was to become Leitz in 1849. When Kellner died and the company was taken over by Belthle and Rexroth, both brothers went to work for Ernst Gundlach. After a couple of business failures, Gundlach emigrated to the United States of America in 1872 and the Seibert brothers took over his loss-making German company with the help of Georg Krafft. Between 1871-1884, the company was known as Seibert and Krafft, and from 1884-1925 as W. & H. Seibert.

The Seibert microscopes have been used by famous microbiologists including Robert Koch.