Finding his forces outnumbered and overextended here, the young prince beat a tactical retreat, but the English army hounded him relentlessly.
The young prince was left with no choice but to divide his forces in the hopes of confusing the English army.  
mnli hypothesis: The young prince was left with no choice but to divide his forces in the hopes of confusing the English army.   premise: Finding his forces outnumbered and overextended here, the young prince beat a tactical retreat, but the English army hounded him relentlessly.