Joko Widodo, Indonesia’s first leader from outside the political and military elite, was sworn in as president on Monday and reached out to political foes to seek support for his ambitious reform agenda.

After the inauguration, Widodo capped his remarkable rise from an upbringing in a riverside slum by travelling through the streets of the capital Jakarta in a horse-drawn carriage, with tens of thousands of flag-waving supporters cheering and shouting his name.

Widodo, a 53-year-old former furniture exporter known by his nickname Jokowi, won the presidency in July after a close race against controversial ex-general Prabowo Subianto.

The former Jakarta governor, who won legions of fans with his man-of-the-people image, is the country’s first leader since the end of Suharto’s three decades of dictatorship in 1998 to have no major links to that era.

Hopes are high for a new style of leadership in the world’s third-biggest democracy, but there are also fears an opposition-dominated parliament could make it hard for Widodo to enact reforms to revive the G20 economy and help society’s poorest.

After taking the oath in parliament at a ceremony attended by dignitaries including US Secretary of State John Kerry and Australian Prime Minister Tony Abbott, he called for unity following the most bitterly fought election in Indonesian history.

“Unity and working hand in hand are prerequisites for us to be a great nation,” said Widodo.

“We will never become a great nation if we are stuck with division.”

“This is a historic moment for us all to move together, to work and work,” the president urged.

The new leader also referred to Prabowo as “my best friend” during the speech, and the ex-general responded by standing up and giving a salute, the latest sign of a thaw between the pair after recent tensions.

After travelling through the streets in the carriage, accompanied by Vice President Jusuf Kalla and a colourful parade of dancers and musicians, he was received at the presidential palace by outgoing leader Susilo Bambang Yudhoyono and watched a military parade.

Later in the evening, Widodo, a heavy metal fan, is expected to take to the stage with rock bands at a huge outdoor concert.