Simplify the following text for a Grade 6 native English-speaking person.
Original: The Muromachi period ended in 1573 when the 15th and last shÅ gun , Ashikaga Yoshiaki , was driven out of the capital in Kyoto by Oda Nobunaga .
Simplified: This period ended in 1573 . In that year the 15th and the last shogun named Ashikaga Yoshiaki was forced to go out of the capital .