Pontefract Castle. The 'Pontefract Castle' on Widmore St. (built between 1719 and 1746) got its name like many other buildings, streets and squares in Marylebone, they are named after the people who built up the area, the estates they held and their family titles. The Duke of Newcastle had held Pontefract Castle in West Yorkshire for the King in 1642 during the English Civil War and it was John Cavendish Holles, Duke of Newcastle who had begun building the area in Marylebone in 1708.