Simplify the following text for a Grade 8 native English-speaking person.
Original: Prior to this , Gates served for 26 years in the Central Intelligence Agency and the National Security Council , and under President George H. W. Bush as Director of Central Intelligence .
Simplified: Prior to this , Gates served for 26 years in the Central Intelligence Agency and the United States National Security Council . Under President George H. W. Bush , Gates served as Director of Central Intelligence .