Simplify the following text for a Grade 5 native English-speaking person.
Original: The Pour le MÃ rite , known informally as the Blue Max , was the Kingdom of Prussia 's highest military order for German soldiers until the end of World War I.
Simplified: The Pour le MÃ rite , was an medal during World War I and is also known as the Blue Max . It was the Kingdom of Prussia 's highest military order until the end of World War I.