Christian, Duke of Brunswick and Lüneburg was the younger son of Henry Julius, Duke of Brunswick and of Elizabeth, sister of Anne of Denmark. He was a champion of the Queen of Bohemia and raised an army for the Protestant cause in the Thirty Years War. Wounded during battle in 1622, his left arm was subsequently amputated and he was awarded full military honours. The Duke visited London in 1625, and although this portrait was probably started during that visit and shows signs of being painted with extreme rapidity, it must have been completed after the Duke's departure. His military achievements are alluded to through martial elements of his costume - he wears armour over a buff jerkin and boots of Cordoba leather falling in soft folds with prominent spurs. The breeches are decorated at the knees with numerous ribbons and metal points and the sash is embroidered with intertwined B's.