MONICA Napper was adopted at birth, brought up in Kenya and England and left as a teenager to explore the world. A dyslexic, she found her medium in pictures and became a photographer. Eight years ago, she landed in Darwin and realised her travels were at an end. For her and her four children, it is now home.

In 2004, Napper began to shoot on the Tiwi Islands, and — counterintuitively to a lifetime of indifference to sport — became fascinated with the football culture there. She says the only sports team she has ever barracked for is the Tiwi Bombers, the composite team that since 2006 has played in the Darwin competition.

On Tiwi Islands' grand final day, a sign freshly painted each year at the oval reads in part: "Please tie up your dogs at home. No gambling on Sunday morning, Please clean up your house on Sunday morning."

A photograph of it appears in Tiwi Footy, a bilingual photojournalism hardback self-published by Napper, fellow photographer Peter Eve and writer Andrew McMillan. The book is as much of a story as its subject. Napper is 42. As recently as her infancy — though, of course, she could not have known it — Tiwi Islanders were all wards of the state, were not allowed to vote, had no access to welfare, were unable to leave their islands without permits and were banned from drinking or marrying outside their own. They were not recognised as citizens until 1967.

They had played football since introduced to it in 1941 by a missionary named Brother John Pye, who blessedly is still with us, aged 101. In his pioneering days, Pye observed that the Tiwis were "that kind of people, athletic, spritely and springy".

"Their kind of football is lightning fast, and it's almost like a religion with them". This is also in the book. But few full-blooded Aborigines played even in the Darwin competition then, and one club was "white only" as a matter of policy.

In 1952, Catholic authorities formed St Mary's, for Tiwis working in Darwin for the armed services. Barefoot and bashful to begin, they quickly adapted, winning the premiership in their third season. St Mary's is now the most successful club in the Northern Territory Football League, with 25 premierships.

Separately, the Tiwis have their own league. In 1973, Maurice Rioli kicked the first goal for the Imalu Tigers in their first Tiwi Islands grand final win; 13 more have followed. Nine years later, Rioli, playing for Richmond, won the Norm Smith Medal. Nine further years on, St Mary's alumnus Michael Long, playing for Essendon, emulated Rioli, and the football world was alert to the Tiwis.

Last week, controversial historian Gillian Hibbins argued that Adam Goodes was racist to suppose that Aborigines had a gift for the Australian game.

Aborigines are disproportionately represented on AFL lists by a factor of four or five and the Tiwis, population 2500, have given us two Norm Smith medallists. If that is chance, it is on an unprecedented scale.

The first VFL grand final Ted Egan saw was 1939. Later, he founded and played for St Mary's, later still became an entertainer and then administrator (governor) of the Northern Territory. " … I have never seen a better representation of the fundamentals of footy than at the Tiwi grand final of 2007," he writes in the foreword to Tiwi Footy. " … For sheer pace, exuberance and brilliant skills at marking, kicking and handballing, there is nothing better than a Tiwi footballer."

Grand final day, dawn to dusk, became the conceit for Napper's book. She co-opted Eve, and McMillan, whose writing she had admired in The Monthly, and spent two years acquainting herself with the politics of the Tiwis and winning the trust of the islanders so that they would act and she could shoot unselfconsciously.

For a year, Napper sought a sponsor and a publisher, unavailingly. So she re-mortgaged her house and with Eve set up a company and published it themselves. The cost was more than $50,000. Napper said her motivation was to give something back to the people and community that so entranced her.

The book exudes charm: of the day, of the place, of the people, the place. "You can see they didn't take much notice of the sign about the dogs," Napper said. The reader is left to feel as if he or she has been there.

Football has grown important as a release and distraction, but for some also as a meal ticket. It just might become the Tiwis' major industry.

Tiwi Footy is available through Essendon Football Club and at gate four at the MCG tonight.