The town was renamed after John Grenfell , the Gold Commissioner at Forbes . He had been killed in 1866 when bushrangers attacked a stagecoach on which he was traveling . Grenfell is a goldmining town first known as Emu Creek and renamed in honor of John Grenfell , Gold Commissioner at Forbes , who had been killed in 1866 when bushrangers attacked a stagecoach on which he was traveling .