Simplify the following text for a Grade 6 native English-speaking person.
Original: But now the leaders of Austria-Hungary , especially General Count Leopold von Berchtold , backed by its ally Germany , decided to confront Serbia militarily before it could incite a revolt ; using the assassination as an excuse , they presented a list of ten demands called the July Ultimatum , expecting Serbia would never accept .
Simplified: They used the assassination as an excuse . They gave Serbia a list of ten demands called the July Ultimatum .