Complex sentence: Pyotr Petrovich Glebov (14 April 1915-17 April 2000), was a Russian film actor from the aristocratic, whose early generations are listed in the 17th-century Velvet Book.
Split into simpler sentences: Pyotr Petrovich Glebov (14 April 1915-17 April 2000), was a Russian film actor from the aristocratic. It's one of the families whose early generations are listed in the 17th-century Velvet Book.