The brig Diadem, 158 tons, was built in Southampton in 1824. Originally owned by N Griffiths and registered in London, she was intended to trade between London and the Straits of Gibraltar, but later followed other routes including those to several Italian ports. After change of ownership in 1845, she did the voyage from London to the Cape of Good Hope in 1846 but she disappears from Lloyd's Registers after 1851.