Complex sentence: Babur's guns proved decisive in battle, firstly because Ibrahim Lodi lacked any field artillery, but also because the sound of the cannon frightened Lodi's elephants, causing them to trample Lodi's own men.
Split into simpler sentences: Babur's guns proved decisive in battle, firstly because Ibrahim Lodi lacked any field artillery but also because elephants are scared of guns. Babur could use the guns to scare the elephants away, causing them to trample Lodi's own men.