This person convoked a synod that selected Guibert   of Ravenna as pope, though Guibert is now known as Antipope Clement the Third.
This man was the two-time brother-in-law of Rudolf of Rheinfelden, who died soon after defeating   this person at the Battle on the Elster. This leader passed his crown on to his younger son after  being deserted by his oldest living son, Conrad. This person convoked a synod that selected Guibert   of Ravenna as pope, though Guibert is now known as Antipope Clement the Third. In what is known  as the Walk to Canossa, this leader supposedly traveled barefoot as penance towards Pope Gregory  the Seventh. Name this Holy Roman Emperor who was involved in the Investiture Controversy.
This man was the two-time brother-in-law of Rudolf of Rheinfelden, who died soon after defeating   this person at the Battle on the Elster.
{Henry} IV, Holy Roman Emperor [or Heinrich IV]