His coronation barely two months hence, Henry IV leaves Rome without being able to capture Pope Gregory VII. The Pope’s powerful vassal, Robert Guiscard, Duke of Apulia and greatest of Norman warlords was approaching with an army of 36,000.
Henry does not fancy a long siege in a malaria infested swamp with a hostile city population. He no longer needs Rome, what he needs to do is get back to Germany and bring peace to the war-ravaged country.
A U-turn in his policies helps to gain support amongst bishops and magnates so that by 1089, the country is largely pacified for the first time in 17 years.