Constantijn Huygens the Younger was the son of statesman and poet Constantijn Huygens the Elder and brother of physician Christiaen Huygens, who invented the wave theory of light. After going to Leiden to study in 1644, Huygens succeeded his father as secretary to stadtholder Frederick Henry, traveling throughout Europe and keeping the first of many diaries. After Frederick Henry's death, the Neth
