Simplify the following text for a Grade 11 native English-speaking person.
Original: By the 1920 Treaty of Trianon , Hungary renounced in favor of Romania all the claims of the Austro-Hungarian Monarchy over Transylvania .
Simplified: After the Treaty of Trianon was signed in 1920 , Hungary , as agreed , gave up the claims of the Austro-Hungarian Monarchy over Transylvania .