title: Blenheim Palace
context: The architect selected for the ambitious project was a controversial one. The Duchess was known to favour Sir Christopher Wren, famous for St Paul's Cathedral and many other national buildings. The Duke however, following a chance meeting at a playhouse, is said to have commissioned Sir John Vanbrugh there and then. Vanbrugh, a popular dramatist, was an untrained architect, who usually worked in conjunction with the trained and practical Nicholas Hawksmoor. The duo had recently completed the first stages of the Baroque Castle Howard. This huge Yorkshire mansion was one of England's first houses in the flamboyant European Baroque style. The success of Castle Howard led Marlborough to commission something similar at Woodstock.[15]
question: Who designed Blenheim Palace?
answers: Sir John Vanbrugh