In his first speech, Di Natale, 44, said he was a testament to Australia's success as an immigrant nation. Senator Di Natale announcing an initiative to restrict alcohol advertising on TV. Credit:James Boddington "My mother and her parents left San Marco, a small village in southern Italy, to board a ship for Australia in the late 1950s," Di Natale said. "They did not speak any English but they sailed off into the unknown armed with something far more important - the hope for a better life. My grandfather opened a grocery shop in Brunswick, took mum and her sisters out of school and put them to work in the shop." His father left Sicily for Australia at 29, did an electrical apprenticeship and worked his life on building sites.

"Their story is a universal one," he said. "It is on their shoulders, and those of millions of families just like theirs, that this nation has been built." Senator Di Natale with former Greens leader Bob Brown. Credit:Pat Scala A trained doctor like Bob Brown, Di Natale studied medicine at Monash University before graduating with a Master of Public Health and Health Science at La Trobe University. He then worked on HIV prevention in India and in remote Aboriginal communities. A natural sportsman known for his soccer and cricket skills, he played in the Victorian Football league for six years. Former Greens leader Senator Christine Milne embraces new Greens leader Senator Richard Di Natale. Credit:Andrew Meares

It's a different background from the man seen as Di Natale's chief rival for the job, Adam Bandt - a former industrial relations lawyer and student Marxist who in his youth accused the Greens of being too "bourgeois". Since entering Parliament in 2010 as a senator for Victoria, Di Natale has built on his background in medicine and sport. He's argued for a national dental scheme, for the legalisation of medical marijuana and for a ban on live betting odds during sporting broadcasts. Senator Richard Di Natale and Adam Bandt arrive for the Greens leadership ballot. Credit:Alex Ellinghausen Late last year, when the government denied him support to travel to Ebola-affected areas in West Africa, he decided to do it himself. Describing himself as a lapsed Catholic, he has also argued for Parliament to scrap readings of the Lord's Prayer, saying it is out of touch with modern Australia.

Senator Di Natale during his pre-Senate days. Credit:Sandy Scheltema "We are here to represent everybody," he said. "We're here to represent people of all faiths." After his elevation to the leadership on Wednesday, Di Natale stressed that he and Milne were "different people". "I came at this through health. I came not from a political background. I spent a few years as a GP and a public health specialist working in places like Tennant Creek and north-east India. It became pretty clear to me that if you want to improve people's health, you've got to start looking at the things that make people sick. You've got to have a clean environment, clean air and clean water. You've got to make sure that people have got a roof over their head, that they've got a decent education, that they've got meaningful work and they've got a social safety net if they get into trouble." Loading

His first task as leader will be to build a profile in the broader electorate, where he is not well known, and to develop authority within the Parliament. Second will be to define the Greens' role under the Abbott government: is it just a party of protest or a party that gets things done? If it's the latter, then a deal with the government on reintroducing fuel indexation - controversially knocked back by Milne last year - could be the place to start.