1956: Previously under British and Egyptian rule, Sudan becomes first country in sub-Saharan Africa to achieve independence.

1958: General Ibrahim Abboud leads Sudan’s first military coup, overthrowing civilian government. Abboud then pursues policy of converting the government to Islam, sowing division between the North and South, as the latter favored secular government.

1964: Riots and protests dubbed “October Revolution” lead to ouster of the Abboud military regime and a return to civilian rule.

1967: Sudan breaks diplomatic relations with the United States, citing American support for Israel in the Arab-Israeli war.

1969: President Jaafar Numeiri assumes power in “May Revolution” and leads socialism movement, including nationalization of banks and private industry.

1972: The Addis Ababa peace agreement ends civil war by giving South Sudan a measure of political independence – including its own executive, legislative, and judicial branches – ushering in a decade of relatively peaceful relations between North and South.

1973: The U.S. Ambassador to Sudan, Cleo A. Noel, is assassinated in Khartoum by members of Black September, a Palestinian terrorist group. When Sudan commutes the sentences of six men convicted in the killing, the United States withdraws its ambassador from Sudan and freezes economic aid to the country.

1978: Chevron discovers oil in southern Sudan.

1983: President Numeiri effectively overturns the 1972 peace agreement, introducing Islamic Shari’a law and declaring Arabic the official language of South Sudan. A 22-year civil war between North and South – Sudan’s second prolonged civil war since nationhood – breaks out. Political division between the North and South, uneven distribution of resources between the central and border regions of Sudan, and oil revenues are considered root causes.

1986: Ahmad Ali al-Mirghani heads up the last democratically elected government of Sudan as Chairman of the Supreme Council.

1989: Current President Omar al-Bashir, head of the National Islamic Front, ousts the democratically elected al-Mirghani government in a military coup. The United States imposes sanctions against the Bashir government for human rights abuses and support for terrorism; sanctions are still in place today.

1999: Sudan’s first oil refinery comes online on the 10th anniversary of Bashir’s rise to power – June 30. In August, Sudan exports its first shipment of crude oil on pipelines built by Talisman Energy, a Canadian company.

2003: Armed conflict begins in Darfur, the western region of Sudan. The United Nations today reports that 300,000 people have died since the hostilities began, many from disease and other consequences of displacement. More than 2.7 million fled their homes.

2004: U.S. Secretary of State Colin Powell calls the violence in Darfur “genocide.”

2004: Trade between China and Africa doubles in a single year, to $18.5 billion, due in large part to China’s heavy investment in Sudanese oil.

2005: The North and South sign a Comprehensive Peace Agreement (CPA), ending the civil war and allowing for a referendum on independence in South Sudan and a revenue-sharing scheme for oil profits.

2009: The International Criminal Court issues a warrant for the arrest of Sudanese President Omar al-Bashir for war crimes committed in Darfur. The following year, the ICC adds a genocide charge.

2010: Small Arms Survey reports that China and Iran accounted for the overwhelming majority – more than 90 percent – of small arms provided to Sudan from 2001 to 2007.

January 2011: In a referendum, 99.8 percent of voters in South Sudan cast ballots to secede and form a new nation, the Republic of South Sudan.

June 2011: Al-Bashir visits China – Sudan’s chief arms supplier and oil purchaser – at Chinese President Hu Jintao’s invitation, despite outstanding ICC warrants for war crimes and genocide against Bashir.

July 9, 2011: July 9, 2011: South Sudan secedes from the Republic of Sudan.