Former Iranian president Akbar Hashemi Rafsanjani has died aged 82.
Iranian state media said that Mr Rafsanjani was taken to hospital because of a heart condition.
Mr Rafsanjani, who served as president from 1989 to 1997, was a leading politician who often played kingmaker in the country's turbulent politics, and supported President Hassan Rouhani.
Mr Rafsanjani was head of the Expediency Council, a body that advises Supreme Leader Ayatollah Ali Khamenei, and in March he won a seat on the clerical body that will one day decide Mr Khamenei's successor.
Mr Rafsanjani's mix of sly wit and reputation for cunning moves - both in politics and business - earned him a host of nicknames such as Akbar Shah, or Great King, during a life that touched every major event in Iranian affairs since before the 1979 Islamic Revolution.
His presence, whether directly or through back channels, was felt in many forms. He was a steady leader in Iran's turbulent years after overthrowing the US-backed shah, a veteran warrior in the country's internal political battles and a covert go-between in intrigue such as the Iran-Contra arms deals in the 1980s.
He was handed an unexpected political resurgence in his later years.
The surprise presidential election in 2013 of Mr Rafsanjani's political soulmate, Mr Rouhani, gave the former president an insider role in reform-minded efforts that included Mr Rouhani's push for direct nuclear talks with Washington.
Mr Rouhani's victory was also another example of Mr Rafsanjani's remarkable political luck. He was blocked from the ballot by Iran's election overseers - presumably worried about boosting his already wide-ranging influence. But, in the end, many liberals turned to Mr Rouhani as an indirect vote for Mr Rafsanjani.
It came after years of dwindling influence. Another presidential comeback bid was snuffed out by Mahmoud Ahmadinejad's surprise victory in 2005 elections, which left Mr Rafsanjani and his powerful clan as fierce critics of Mr Ahmadinejad.