Complex sentence: Delaval's greatly outnumbered blue squadron fought a desperate battle with d'Estrées in the rear, but Evertsen in the van, having lost his second-in-command and many other officers, was forced to draw off.
Split into simpler sentences: Delaval's greatly outnumbered blue squadron fought a desperate battle with d'Estrées in the rear. Evertsen however, having lost his second-in-command and many other officers, was forced to draw off.