Simplify the following text for a Grade 8 native English-speaking person.
Original: Marcus Ulpius Nerva Traianus ( 18 September 53 â `` 9 August 117 ) , commonly known as Trajan , was Roman Emperor from 98 to 117 .
Simplified: Trajan ( Marcus Ulpius Nerva Traianus , 18 September 53 â `` 9 August 117 ) was Roman Emperor from 98 to 117 .