Simplify the following text for a Grade 8 native English-speaking person.
Original: The arena continued to be used for contests well into the 6th century , with gladiatorial fights last mentioned around 435 . Animal hunts continued until at least 523 , when Anicius Maximus celebrated his consulship with some venationes , criticised by King Theodoric the Great for their high cost .
Simplified: The last record of gladiator fights is about 435 , while animal hunts continued until at least 523 .