General Dupont's had, from my inexpert view, quite a superior army when he fought the Spanish forces at the Battle of Bailén. This battle was in fact the first defeat in open field of the Napoleonic army.
It is true that the Spanish were better provisioned by the population of the city of Bailén and that the lack of communication with his other battlions got Dupont surrounded by Spanish forces. But still, he counted with a much more experienced army and could have, again in my view, attempted a retreat even at the cost of loosing part of his army.
I had the suspicion that perhaps he was trying to save his own life. This view is now somewhat confirmed by the fact that when he came back to France he was deprived of all his privileges and put into jail. I suspect that this process was carried out by the suspicion that he did not do all he could to resist the trap he was in.
So, why did General Dupont's surrender at Bailén, marking probably the begin of the end of the I French Empire?