Hanging in the foyer of the Australian Centre for Contemporary Art (ACCA) right now is a five-metre-long banner by artist Reko Rennie. In fluorescent camouflage, and emblazoned with the words “ALWAYS HERE”, it’s enormous and unmissable. Rennie’s piece works perfectly as an introduction to Sovereignty, ACCA’s new show focusing on contemporary art by Indigenous people from across Australia’s south-east.

The message is clear and bold: sovereignty was never ceded, and the art herein is about aggressively re-asserting Indigenous cultures.

Max Delany, ACCA’s artistic director, and Paola Balla, a Wemba-Wemba and Gunditjmara woman, curated the show together.

“When we meet with artists and community members,” says Delany, “it’s always about art, social history, family, community, culture, politics, all at once. It’s all entwined, so we knew it had to be a complex show.”

For Delany, the show springs from the influence of William Barak, who was an artist, elder, diplomat and activist. Barak was there at the beginning, when Batman signed the contested treaty to take control of the land that Melbourne now occupies. His art discussed the culture clash between Indigenous people and Europeans. Several of his works, dating back to 1897, are included in the show. Beyond that, Sovereignty focuses almost entirely on the past decade.

Artistically, there’s a mix of media and influences. Some artists renew longstanding cultural practices, celebrating their heritage. Glenda Nicholls’s A woman’s right of passage (2015) is three wool, jute and possum-skin woven cloaks, representing three stages of a woman’s life: welcome, acknowledgement and becoming an elder.

Others more consciously engage with – and subvert – contemporary Australian society, looking for hints of their own identity in a whitewashed culture.

“We don’t see a lot of our culture represented in the built environment,” says artist Kent Morris, a Barkindji man. “I feel uncomfortable walking around where I live.

“I know that underneath the concrete is the land the ancestors walked on, but I don’t see much reflected above that. It makes a lot of us feel unsafe.”

Morris’s series, Cultural Reflections – up above #2, is about appropriating white spaces. Morris photographs unremarkable details of city skylines – Federation-style rooftops, an overpass over Dandenong Road, powerlines in Broken Hill, Darwin Convention Centre – and reshapes them into geometric forms he’s based on designs found on traditional objects, such as shields and boomerangs.

“This has all been overlaid on our country,” he says. “I’m bringing back some cultural space, to recognise that we’re still here.”

There are film works scattered throughout, including Bastardy, Amiel Courtin-Wilson’s documentary about the troubled life of actor Jack Charles; Black Fire, a fascinating documentary about the black-power movement at Monash University made in 1972 by Bruce McGuinness; and two incendiary music videos from rapper Briggs.

A big part of the show’s boldness – and a benefit of ACCA’s high ceilings – is the scale of a lot of the work. Apart from the aforementioned Reko Rennie piece, there’s Brook Andrew’s imposing five-metre-wide balloon entitled The weight of history, the mark of time (2015), and a wall of banners from the Warriors of the Aboriginal Resistance (WAR) proclaiming “REVIVE, DECOLONISE, RESIST”, “NO CLIMATE JUSTICE ON STOLEN LAND”, “BLACK LIES, WHITE LIVES”.

The exhibition comes at an exciting time for Indigenous art in Melbourne. The whole third floor of NGV Australia is currently dedicated to the work of Indigenous women. And around the corner at ACMI, Lynette Wallworth's Collisions uses virtual reality to immerse us in the violence of first contact.

Delany assures me this wasn’t planned. “The scheduling is happenstance,” he says. “But culturally it’s no coincidence. There’s an incredible resurgence being driven by a lot of smart young people.”

Sovereignty runs at ACCA until March 26.