Simplify the following text for a Grade 7 native English-speaking person.
Original: Jorge died in 1479 during an attempt to take the castle of GarcimuÃ oz , defended by Marquis of Villena ( a staunch enemy of Isabel ) , after Isabel gained the crown .
Simplified: Jorge died in 1479 during an attempt to take the castle of GarcimuÃ oz after Isabel gained the crown .