Complex sentence: However, Loison failed to clear Silveira's force away from Soult's planned path of retreat to the northeast, so Soult was compelled to abandon all his equipment and take footpaths over the hills to the north.
Split into simpler sentences: However, Loison failed to clear Silveira's force away from Soult's planned path of retreat to the northeast. So, Soult was compelled to abandon all his equipment and take footpaths over the hills to the north.