1792 - moved to London from Alsace; worked in instrument workshop of Jesse Ramsden (1735-1800);

1794 - set up business, initially as a partnership with Francis Rousset;

1795 - began making tools and lathes; firm founded;

1804 - partnership with assistant John George Deyerlein; Business conducted under the name Holtzapffel & Deyerlein, and lathes began to be numbered (nearly 1000 lathes made); located at 64 Charing Cross Road, London;

1827 - Deyerlein left the partnership; John Jacob's son Charles joined the firm;

1836 - John Jacob Holtzapffel I dies and company run by his son Charles