Although popular sayings say that the oldest profession in the world is that of prostitution, I would say that it is that of soldier or warrior depending on the time. If something has characterized all societies and at any time in history, it has been wars. Regardless of the reasons that caused them and the fools who declared them, the origin of all of them can be summed up in these words of Voltaire :
A genealogist tests a prince who is descended in direct line from an earl whose parents entered into a family pact three or four hundred years ago with a noble house of which not even memory exists.
This house had vague claims to a province whose last possessor died of apoplexy. This province uselessly protests against the supposed rights of the prince; he says that he does not want to be governed and states that in order to dictate laws to vassals, they have to consent to it; but the prince ignores these protests because he believes his incontestable right. He gathers a multitude of men, dresses them in thick blue cloth, commands them to march to the right and left, and goes with them to glory.
Other princes hear of this great number of men in arms and take part as well. in the company, each according to his power, and fill an extension of the territory with mercenary assassins. Crowds come and rage against each other, not only having no interest in the war but not knowing why it is promoted.
The wonderful thing about this infernal enterprise is that each leader of the assassins has their flags blessed and summons God solemnly before going to exterminate his neighbor. When a chief only has the fortune to slaughter two or three thousand men, he does not thank God; but when he manages to exterminate ten thousand and destroy a city, then he has the tedéum sung.
Source:The anecdotes of politics – Luis Carandell Image:Círculo de Bellas Artes