Complex sentence: Russian War (1605--18) was a part of the regiment under the command of Wilim Grim, later captain-rittmeister Jacob Shaw switched sides and in 1614 left the fortress of Bely to join under Russian control.
Split into simpler sentences: Russian War (1605--18), was part of the regiment under the command of Wilim Grim. Later captain-rittmeister Jacob Shaw switched sides and, in 1614, left the fortress of Bely to join under Russian control.