Danish-born Charles Frederick de Brocktorff (1775-1850) fought in the Napoleonic Wars as an infantry officer with the forces of the Electorate of Hanover before settling in Malta in c.1810, where he opened an art studio in Valletta.
This 8in (20cm) square portrait miniature of a naval officer is signed de Brocktorff pinx and is estimated at £400-600 in the July 3 auction at Boningtons in Essex.