Curlew Fugitive by Don Douglas.
In this third novel of the Curlew series, fifteen year-old Ben McDonald goes on the run from the law after his temper causes an unfortunate incident at the 1900 Melbourne Cup and leaves a man dead.
From the Palmer River to the Top End and the Golden Mile, the trenches of Gallipoli and desert warfare with the Light Horse, danger and catastrophe dog his life. Every bit of tenacity he's inherited from his illustrious Grandmother, Eliza, is needed as he battles the odds and strives to achieve. His friendship with a suave Englishman, Basil Southerland, has unexpected and ongoing ramifications for his future and that of succeeding generations.