In April 2011, Barcelona and Real Madrid faced each other four times in just 18 days: twice in Champions League semi-finals, once in La Liga, again in the Copa del Rey. Those 18 days descended into a strained, feverish period that de ned an era for one of football's most intense rivalries.
Barcelona was Guardiola's past and his present. Born and raised in Catalonia, he had grown up at the club,...