Simplify the following text for a Grade 10 native English-speaking person.
Original: Gaius Julius Caesar Augustus ( 23 September 63 BC â `` 19 August AD 14 ) is considered the first emperor of the Roman Empire , which he ruled alone from 27 BC until his death in AD 14 .
Simplified: Augustus ( Gaius Julius Caesar Augustus , 23 September 63 BC â `` 19 August AD 14 ) was the first and one of the most important Roman Emperors .