Award-winning Australian author John Marsden, best known for his multimillion-selling Tomorrow series, has died aged 74.
Tomorrow, When The War Began, released in 1993, sold millions of copies around the world and was adapted as a film in 2010.
The book was dubbed "the best series for Australian teens of all time" and was the first in his seven-book Tomorrow series.
READ MORE: How police uncovered the alleged double homicide of Sydney couple
The Candlebark and Alice Miller Schools, which he founded, confirmed his death tonight, describing his contribution to young adult literature as "revolutionary" and hailing his "unflinching honesty in addressing complex themes".
"John Marsden transformed countless young lives through both his writing and his groundbreaking approach to education," the schools said.
"As one of Australia's most beloved and successful authors, he sold more than 5 million books and was translated into 15 languages."
Marsden was born in Victoria in 1950 and decided he wanted to become an author at the age of nine.
But he took a winding path to literary stardom via time spent working in an abattoir, as a lorry driver, and in the emergency ward in a hospital.
He then worked as a teacher at schools including Geelong Grammar's Timbertop and Fitzroy Community School before publishing his first book, So Much To Tell You, in 1987.
Marsden went on to write more than 40 novels.
His Tomorrow series and The Ellie Chronicles gained him notoriety and were loved especially by teenage readers.
READ MORE: No methanol in cocktails that made seven ill as Aussie flown home
Marsden won the Lloyd O'Neil Award for contributions to Australian publishing in 2006.
According to his publisher, Pan Macmillan Publishing, he won every major award in Australia for young people's fiction.
Marsden never gave up teaching and even bought an estate on the northern edge of Melbourne in 1998, where he ran a popular writing course.
He later turned the property into his own P-8 school, Candlebark, in 2006.
He stepped down from his role as a principal at Candlebark, as well as 7-12 school Alice Miller, earlier this year.
"John was a true champion of children and young people. He had unflinching belief in them and viewed them with profound respect," current principal Sarita Ryan said.
"The schools were designed to allow students to be authentic, expressive, and highly capable given the right opportunities.
"John never viewed Candlebark and Alice Miller as particularly radical, as in his mind the schools 'just did the bleeding obvious'."
DOWNLOAD THE 9NEWS APP: Stay across all the latest in breaking news, sport, politics and the weather via our news app and get notifications sent straight to your smartphone. Available on the Apple App Store and Google Play.