Some southerners in traditional dress carried shields and wore ostrich feathers, but most wore urban attire – jeans and T-shirts – at their first rally in the capital in more than two decades.
"Peace, oh yes, new Sudan, oh yes," the crowd of around 10,000 people chanted on Wednesday as leaders of the Sudan Peoples Liberation Movement (SPLM) gave speeches.
The highest-level delegation from the former rebel SPLM since civil war began in 1983 arrived in Khartoum last weekend to begin forming a coalition government after signing a peace deal in January.
"Peace has dawned at last in our war-torn nation," said the delegation head, SPLM secretary-general James Wani.
"The SPLM did not come here just to take up 10 or 20 ministerial posts. We came here as a movement for change - this is the new Sudan"
southern rebel leader
Senior SPLM official Yasir Arman said they had come to unite Sudan.
"The SPLM did not come here just to take up 10 or 20 ministerial posts. We came here as a movement for change - this is the new Sudan," he said.
Many in the crowds were ecstatic at the arrival of the delegation, whose first major task will be to form the new constitution.
"We have met them again after 21 years of absence," Manshur Malwal Kwot, from oil-rich Abyei, said.
"This new government will be one of participation, to include all the groups – not like now."
The southern civil war broadly pitted the Khartoum-based government against rebels who were mostly Christian or practised traditional animist religions.
The rally marked the first political
meeting in Khartoum in 21 years
The war claimed two million lives and forced more than four million from their homes.
Despite the peace deal, the United Nations said on Wednesday that a UN-chartered plane had been shot at while landing near Juba on 2 April by unknown men.
And not everyone in the crowd was happy with the peace deal, which gives the south a right to choose secession after six-and-a-half-years.
"I don't want this peace," said Simon Njok. "I want separation – I have lived through betrayal here in the north".
The southern peace deal does not affect a separate conflict raging in the western region of Darfur.