Question: Mexican general, Gregorio Ruiz, fought against the ensuing empire of the younger brother of the Austrian emperor Francis Joseph I, the only what of the Second Mexican Empire?
Sentence (from "Maximilian I of Mexico"): France (along with the United Kingdom and Spain, who both withdrew the following year after negotiating agreements with Mexico's democratic government) had invaded Mexico in the winter of 1861, as part of the War of the French Intervention.
Relevant evidence: No