Simplify the following text for a Grade 11 native English-speaking person.
Original: Igor Mikhailovich Diakonov ( December 30 , 1914 ( January 12 , 1915 ) , Petrograd â `` May 2 , 1999 , St Petersburg ) was a Russian historian , linguist , and translator who should be ranked among the greatest authorities on Ancient Near East and its languages .
Simplified: Igor Mikhailovich Diakonov was a Russian historian , linguist , and translator and a renowned expert in the Ancient Near East and its languages .