Henry Aaron Stern (1820 85), of German Jewish birth, moved to London in 1839, converted to Christianity and became a lifelong missionary for the London Society for Promoting Christianity amongst the Jews. With his wife he preached in Palestine, Babylon, Constantinople, Baghdad, Persia, and to the Karaite Jews of the Crimea. Famously, in 1863, he was caught in a diplomatic dispute in Ethiopia that led to his imprisonment and eventual rescue, five years later, by a British military force. Stern was made a doctor of divinity in 1881. He wrote three memoirs, which were drawn on by Albert Augustus...