The historical background for this episode was the Second French Intervention in Mexico (1861-67). To extend the influence of Imperial France, Napoleon III instigated the intervention in Mexico by claiming that the military adventure was a foreign policy commitment to free trade. Maximillian I was installed as Emperor of Mexico and was a puppet ruler for French interests.
Ortega's closing quote - "Who overcomes by force, hath overcome but half his foe"- is from the 1667 epic poem Paradise Lost by John Milton.