Simplify the following text for a Grade 12 native English-speaking person.
Original: But finally he decided for Rudolph of Swabia after his victory at Flarchheim ( January 27 , 1080 ) and declared the excommunication and deposition of King Henry again ( March 7 , 1080 ) .
Simplified: Finally he decided for Rudolph of Swabia after his victory at Flarchheim ( January 27 , 1080 ) . Under pressure from the Saxons , and misinformed as to the significance of this battle , Gregory abandoned his waiting policy and again pronounced the excommunication and deposition of King Henry ( March 7 , 1080 ) .