Simplify the following text for a Grade 7 native English-speaking person.
Original: The Napoleonic Wars ended following Napoleon 's final defeat at Waterloo on 18 June 1815 and the Second Treaty of Paris .
Simplified: The Napoleonic Wars ended on 20 November 1815 . This was just after the Battle of Waterloo , a big battle that Napoleon lost , and the Second Treaty of Paris in 1815 .