Simplify the following text for a Grade 13 native English-speaking person.
Original: In 1999 , a proposed preamble , principally authored by John Howard , the then Prime Minister , was defeated in a referendum held concurrently with the Republic referendum .
Simplified: In 1999 , a proposed preamble , written by John Howard , the then Prime Minister , was defeated in a referendum held concurrently with the Republic referendum .