Werner von Siemens retired from active management of the company in 1890. He was succeeded by his sons Wilhelm and Arnold, who took over the leadership together with their uncle Carl. Siemens & Halske was re-formed as a stock corporation in 1897. This was an essential step in order to cover the company’s expanding capital requirements.

In 1903, Siemens & Halske acquired the company Elektrizitäts-Aktiengesellschaft vorm. Schuckert & Co., merging it with its own power engineering unit to form Siemens-Schuckertwerke GmbH. As electrical engineering advanced, numerous new sectors were added over the years to the two parent companies’ traditional power engineering and communications engineering businesses, and the purpose of the new company was to cover all areas of electrical engineering.

Also in 1903, Siemens and AEG co-founded the Gesellschaft für drahtlose Telegraphie System Telefunken, which specialized in developing the new field of radio.

Siemens’ expansion eventually necessitated concentrating manufacturing and administration at a single, large-scale location. The company therefore purchased the Nonnenwiesen, a green-field site in the northwest of Berlin, in 1897. Only two years later the Westend cable factory went into operation at the new location, and by 1913 all company activities had been relocated to the new campus known as Siemensstadt.

One interesting innovation to emerge in connection with the creation of the new industrial park was the parallel development of an area of workers’ housing, complete with the requisite infrastructure. By 1914, Siemensstadt’s population had reached 7,000. This and the fact that more than 20,000 people worked there made the provision of public transport essential.

The company also recorded several notable technological achievements in the field of rail transport. In Budapest, it built continental Europe’s first underground rail line, which took just two years to complete and opened in May 1896. In 1903, a high-speed locomotive developed by Siemens set a new world speed record of 210 km/h. The most prominent innovation in the area of telecommunications engineering during this era was introduced with the commissioning of the first metropolitan automatic telephone exchange, which was built in Munich’s Schwabing district in 1909 and had a capacity of 2,500 line units.

By fiscal 1914, Siemens had a worldwide workforce of 82,000 employees, of whom a quarter worked outside Germany, and the company had become one of the world’s foremost players in its industry. The outbreak of World War I caught Germany’s electrical industry entirely unprepared and had a substantial and lasting impact on its global standing. Siemens’ markets collapsed, and the majority of its foreign subsidiaries were expropriated.