Task: Question Generation
Input (English): Context : Vice-Admiral Sir John Tremayne Rodd, KCB (c. 1769 -- 4 October 1838) was an officer of the Royal Navy noted for his services during the Napoleonic Wars. 
Subject : John Tremayne Rodd 
Relation : military branch
Output (English): Which armed forces did John Tremayne Rodd serve?