Career
Simonis was Mayor of Luxembourg City from 1873 until his premature death, in 1875. He also sat in the Chamber of Deputies. In the Chamber, he was notable for his leadership of the campaign against the creation of a National Bank, which he maintained until his death.
Simonis was one of 26 subscribers, along with various other notable liberal politicians, to the Companie des Hauts Fourneaux Luxembourgeois.