The hot summer sun beat down on 72-year-old John (Don Juan) O’Brien as he slowly mounted the wooden platform in the Plaza de Armas in Lima, Peru. The Cathedral of Lima (below-left) loomed above the plaza that 28th of July, 1858, just as it had on the same day in 1821. On that day, O’Brien had stood proudly next to General José de San Martín, the great hero of the successful revolutions against S…