Constantine Nicolaievitch, second son of the Czar Nicholas I.; was appointed grand-admiral while but a boy; had command of the Baltic fleet during the Crimean war; came under suspicion of sinister intriguing; became insane, and died in seclusion (1827‒1892).
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Constantine I. * Constantine Paulovitch