Although they date back in some cases more than five centuries, most of these laws or customs evolved as a result of the European experience in the Thirty Years' War as no one in their right mind wanted a repetition of that calamity.
Vattel and Martens appear to have been the most widely-read commentators on these laws and both authors go into some detail on the proper treatment of unoffending civilians, particularly women, by armies.
I do not think there is any dispute on this Forum that Massena's army did not try to follow the accepted customs/laws/usages of war in Portugal in 1810-1811 as the evidence is pretty overwealming. This then would lead to the question of whether France, as is evidenced by the behaviour of her soldiers in the Iberian Peninsula, particularly Portugal in 1810-1811, was a "civilized" nation. That I think would be the subject of endless debate.
I am more interested in the question of what steps Massena and his senior subordinates took to prevent these atrocities. We are assured he issued orders to prevent them but, beyond that, did he or his senior officers take any real steps to prevent such atrocities, or to apprehend and punish the perpetrators.
That is what interests me because I know that, on occasion, British soldiers were guilty of misconduct toward Portuguese and Spanish civilians but that steps were taken to prevent such acts and to apprehend and punish the offenders. These steps were not always successful but at least a very real attempt was made.
This does not seem to have been the case with the French. It would appear to me that, at this point, the French army in the Peninsula was an ill-disciplined force and more or less out of control. If this is the case the responsibility lies with the senior officers and him who sent them.
I think it is clear by now to any readers of this Forum that I do not share the same admiration or awe for Napoleon Bonaparte, his regime and his army that many readers do. As I said in a previous message, however, if you drag the man and his works out of the memorial chapel of his myth -- so dimly lit by votive candles to his genius -- into the cold light of day, he is not quite the super hero, many of his adherents believe him to be.
The behaviour of French troops in the Iberian Peninsula, to me at least, demonstrates the real nature of his regime which, as I remarked before, was a military dictatorship put in place by bayonets and maintained in place by the same bayonets and secret police.
By their works, you shall know them.
dg