Complex sentence: Mahon settled at Menzies as the publicly active proprietor of the Menzies Miner and in 1897, after a campaign which left him discredited, stood unsuccessfully against his rival H. Gregory for the new North Coolgardie seat.
Split into simpler sentences: Mahon settled at Menzies as the publicly active proprietor of the Menzies Miner. In 1897, after a campaign that left him discredited, Mahon stood unsuccessfully against his rival H. Gregory for the new North Coolgardie seat.