HEADS of state, royalty, prime ministers and a host of other dignitaries are set to arrive in the Nigerian capital Abuja on Friday, as preparations step up for ceremonies marking the end of military rule. Olusegun Obasanjo is due to be sworn in Saturday as Nigeria’s third elected president, ending more than 15 years of military regimes in Africa’s most populous country. The 62-year-old retired general, elected in polls in February, will replace General Abdulsalami Abubakar, the outgoing head of state who will quit the army after handing over power. Among the foreign dignitaries, President Nelson Mandela, breaking campaigning for Wednesday’s elections, and Britain’s Prince Charles, representing the former colonial power here, are expected to share star guest billing.