Yvonne Margarula (1962 -)  was born in the bush of the South Alligator area of the Northern Territory’s vast Kakadu National Park. Regarded as the senior Elder of the Mirrar Gagudju, she is responsible for the welfare of the adults and many children making up the clan and their country. She is also the legal title- holder under the white law that gave the Mirrar rights to control their land in 1982.

Jacqui Katona (1966 - ) a Djok woman, from the Kakadu area of the Northern Territory is an Aboriginal advocate. She has worked for the Royal Commission into Aboriginal Deaths in Custody, the Stolen Generations Northern Territory and assisted her family to prevent uranium mining at Jabiluka in Kakadu National Park. She is currently completing her graduate law degree at the University of Melbourne and works at Moondani Balluk Institute located at Victoria University.

The Mirrar, an Aboriginal Australian people, led by Margarula and Katona, mounted a large campaign in opposition to the proposed Jabiluka 

uranium mine in the Northern Territory of Australia. They used legal action and education to gain national and international support. In March 1998 the Mirarr, together with environmental organizations, used massive on-site civil disobedience to create one of the largest blockades in Australia's history.

Over several months, approximately 5,000 people from across Australia and around the world travelled to the remote camp to protest with the Mirarr people. In July the land was cleared by Energy Resources of Australia and construction of the entrance to the Jabiluka mine began; however, protesters intervened and about 550 were arrested, including Margarula and Katona.

A timeline of this action is as follows:
 

• 1997 December: Yvonne Margarula begins Federal Court action against Jabiluka lease. “Jabiluka” documentary launched in Jabiru and Gunbalanya, NT.

• 1998 January: European Parliament passes resolution condemning the Australian government’s approval of Jabiluka.

• 1998 February: Mirarr tour, campaign grows nationally.

• 1998 March: Blockade camp established on Mirarr land within Kakadu. Regular protest action begins at Jabiluka.

• 1998 May 19: International Day of Action to Stop Jabiluka. Yvonne Margarula arrested with three other Bininj for trespass on her land.

• 1998 June: Yvonne Margarula attends UNESCO World Heritage Bureau meeting in Paris resulting in a high-level Mission nominated to visit to report to the World Heritage Committee on whether mining causes Kakadu to be ‘World Heritage In Danger’.

• 1998 August: Yvonne Margarula, Jacqui Katona, Christine Christophersen and Dave Sweeney attend over 40 meetings and events in Europe.

• 1998 September: Legal challenge brought by Yvonne Margarula to the approval of the Public Environment Report by Senator Robert Hill. Federal Election is called, Jabiluka is an election issue.

• 1999 February: Yvonne Margarula appeals her conviction for trespass in Supreme Court of Northern Territory. Environment Minister Robert Hill rejects Mirrar concerns regarding sacred site threatened by ongoing construction at Jabiluka at a meeting with Yvonne Margarula in Canberra.

• 1999 March: Supreme Court rejects Yvonne Margarula’s appeal against trespass charge. North Limited premises blockaded for four days by protests against Jabiluka.

• 1999 April: Yvonne Margarula and Jacqui Katona win the Goldman Environmental Prize for grassroots environmental activism. Hosted by First Lady Hilary Clinton in US White House.

• 1999 June: 37 US Congress members led by Cynthia McKinney write to President Clinton urging action in support of Mirarr and protection of Kakadu.

• In 2011, Margarula wrote a public letter to Ban Ki Moon, Secretary General of the United Nations, expressing sorrow that uranium from Mirarr land was used in the Fukushima plant.
  
  The were awarded the 1998 Friends of the Earth International Environment Award and the 1998 Nuclear-Free Future Award and also won the 1999 US Goldman Environmental Prize in recognition of efforts to protect their country and culture against uranium mining.
  
  Jacqui and Yvonne were instrumental in forging a coalition between Aboriginal Australians and environmentalists opposed to uranium mining in Kakadu park and increased links to anti-nuclear activists. It was a ‘green-black’ alliance which observers claim is unprecedented in the nation’s history.