Complex sentence: The Russian position at Krasny formed gradually on successive days following November 15, when the 3,500 strong flying advance guard of Adam Ozharovsky reached Krasny, and the 17,000 troops of Miloradovich took position alongside the eastern road leading into Krasny from Smolensk.
Split into simpler sentences: The Russian position at Krasny began forming on November 15, when the 3,500 strong flying advance guard of Adam Ozharovsky reached seized the town. That samde day the 17,000 troops of Miloradovich took position alongside the eastern road leading into Krasny from Smolensk.