1847 - Siemens was founded as Siemens & Halske by Werner Siemens (1816-1892) and his brother, Johann George Halske in Berlin.

1897 - Siemens & Halske merge parts of its activites with Schuckert & Co. to become Siemens-Schuckert.

1919 - Siemens & Halske with two other German lighting companies formed Osram GmbH KG (Osram a trade name composed from osmium & wolfram).

1932 - Reiniger, Gebbart & Schall; Phonix AG; and Siemens-Reiniger-Veifa mbH merge to form Siemens-Reiniger-Werke AG.

1966 - Siemens & Halske, Siemens-Schuckert and Siemens-Reiniger-Werke AG merge to form Siemens AG.