From 1840 he was inspector-general of public libraries, and in 1860 became inspector-general in the department of higher education.
From 1847 he took an active part in politics, and in 1860 was chosen an Italian senator, at the same time becoming inspector-general of the Italian telegraph lines.
The Duma endorsed this all but unanimously, and as the result the Grand-dukes Peter and Sergius resigned their posts of inspector-general of Engineers and Ordnance respectively, and the Grand-duke Nicholas his chairmanship of the Committee of National Defence.
On the reorganization of the war office and the higher commands in 1904, the duke was appointed to the new office of inspector-general to the forces, from which he retired in 1907, being then given the new post of commander-in-chief in the Mediterranean, stationed at Malta, which he held until 1909.
He held the office of engineer-inchief of mines in France from 1833 until 1847, when he was appointed inspector-general; and in 1861 he became vicepresident of the Conseil-General des Mines and a grand officer of the Legion of Honour.
