President: Michael Sata (deceased)
Mr Sata came to power in elections in 2011
Michael Sata, who won the presidency in elections in September 2011, died while in office October 2014.
He died aged 77 at a London hospital where he had been receiving treatment for an undisclosed illness. Concern for his health had been mounting and he hadn't been seen in public since returning from the UN General Assembly the previous month, where he failed to make a scheduled speech.
Acting president Edgar Lungu led the celebrations marking the 50th anniversary of Zambia's independence a few days before Mr Sata died.
In the 2011 elections Mr Sata defeated the incumbent, Rupiah Banda, whose Movement for Multi-Party Democracy, had been in power for twenty years.
The elections were marred by outbursts of violence which left two people dead, but the new president was sworn in within hours of the election result being declared.
Mr Sata became president on his fourth try, having previously been a member of the governing party. He vowed to transform the fortunes of Zambia, which is one of the world's largest producers of copper.
He replaced Rupiah Banda, whose Movement for Multi-party Democracy ruled since Frederick Chiluba unseated independence leader Kenneth Kaunda in the first democratic elections in 1991.
Although apparently showing signs of his age when he was elected at 74, Mr Sata tapped into the grievances of the youth and the urban poor who feel left out of the impressive economic growth in Africa's biggest copper producing nation.
Mr Sata's Patriotic Front party vowed to bring back a 25% windfall tax on mining revenues that Banda's government abolished in 2009.
The increase in copper prices since then - from around $3,000 a tonne to almost $10,000 - and the friendly tax regime have drawn a rush of foreign and investment to Zambia, particularly from China.
Since taking office, his administration has frequently denied permits to opposition protests, and launched a raft of corruption cases against former officials now in opposition, including his predecessor, Mr Banda.