Wilhelm Grillo

[1] His ventures spanned Essen, Mülheim, Hamborn, Oberhausen, Gelsenkirchen, Herne, and Wanne.

The Grillo gasworks provided lighting for the factory's own network and Oberhausen's municipal gas grid.

Grillo's activities significantly contributed to the industrial development of Oberhausen, Hamborn, and Mülheim an der Ruhr.

With 1, 400 employees, it generates annual revenue of approximately €860 million and remains wholly owned by Wilhelm Grillo's descendants.

The couple had nine children: four daughters and five sons, including Wilhelm (1845–1888), Julius (1849–1911), Friedrich (1858–1919), and August (1861–1895).

The family tomb of Wilhelm Grillo, adorned with a marble angel sculpture, is located in Düsseldorf's North Cemetery.
A founder's share of the Actien-Gesellschaft Eisen-Industrie zu Stirum for 1, 000 Prussian thalers, issued in Styrum on 1 February 1858, and made out to Friedrich Grillo in Essen, bears signatures from board members, including Friedrich Grillo, Ernst Nedelmann, and Daniel Morian. This ironworks, established by Wilhelm Theodor Grillo, was among the most significant companies in the Ruhr coal region during its time.