David Morbe had paint on his jeans, his shirt, his hands and his black-rimmed glasses. Beads of sweat clung to his forehead and ran down his back, past the inch-long shrapnel scar.

Chisel in hand, he walked slowly around his giant sculpture, carefully inspecting the detail on the eagle crest in front, and the name inscribed on the back - John Garang de Mabior.

Morbe knew that nothing he created would ever be as important as the 4m-tall statue of South Sudan's liberation hero that he and his two fellow sculptors had conceived and built.

It was Saturday in Juba, the southern capital. In a matter of hours, tens of thousands of people, virtually all of whom had suffered in some way during nearly 40 years of conflict since the end of colonial rule, would surround the statue on this dirt field to celebrate the birth of their nation, after a tragic false start 55 years ago. "The independence of Sudan back then was the beginning of slavery in South Sudan," said Morbe, 35. "This is going to be the real independence for our people."

The moment arrived in sweltering heat yesterday. Watched by dozens of heads of state, including Sudan's Omar al-Bashir, the south's wartime enemy, southern President Salva Kiir unveiled Morbe's statue to huge cheers. Christian and Muslim leaders said prayers, and Sudan's national anthem played.

Soldiers and traditional dance troupes paraded by before the Speaker of the southern Parliament read the independence proclamation. The Sudanese flag was lowered, and the flag of South Sudan raised. Kiir took the oath of office. The north-south, Arab-non-Muslim divide that has always existed in Sudan was made official; the country split in two. "We congratulate our brothers in the south for the establishment of their new state," said Bashir. "The will of the people of the south has to be respected."

In the huge crowd, where boys held up paper flags and women ululated, emotions were barely contained. Many of the elated southerners seemed stunned that the day had arrived, which was perhaps unsurprising, given the mistrust that has existed between the north and south. Indeed, when Bashir and the then rebel leader Garang signed a peace deal to end the second, 21-year-long civil war in 2005, many doubted it would last.

The agreement allowed for a six-year interim period where the south would govern itself, and have an equal share with the north of the revenues from the oil produced from beneath its own soil.

The prize at the end of the transition was a vote for southerners on unity or secession.

Garang advocated unity - the southern struggle was a struggle for marginalised people all over Sudan, he argued - but when he was killed in a helicopter crash just a few months after the peace deal the notion of unity died with him. In the referendum in January, 99 per cent of voters chose secession.

The results spoke less of southern unity than a desperate desire to rid themselves of the decades-long oppression by the northern government.

When it achieved independence from Britain in 1956, Sudan was two distinct regions and peoples joined into one: a dry, Arab-dominated north, and a more lush, ethnically African south.

The tension and suspicions were already rife; southern rebels had already taken up arms the year before, fearing, correctly, that the Arab leaders in Khartoum would exploit them.

That first war lasted 17 years, and claimed hundreds of thousands of lives. Peace lasted from 1972 to 1983, before Garang launched a new rebellion led by his Sudan People's Liberation Army.

Last year, Morbe, the sculptor, together with two other southern fine arts graduates, Anthony Gordon and Emmanuel Mateayo, came up with the idea of a giant sculpture to commemorate the new nation. After presenting the proposal to the government's council of ministers, they received the go-ahead and a budget - and the news that the statue would be the centrepiece of the independence celebrations. Said Morbe: "I am so proud to have been part of this moment."