Twenty years of frosty relations

The SAS ended the 1980 siege at the Iranian embassy

Jack Straw's visit to Tehran next week underlines recent improvements in diplomatic relations between Britain and Iran, which were beset by trouble in the 1980s and '90s.

It is the first time a UK foreign secretary has visited the country since the 1979 Islamic revolution which overthrew the Shah and brought Ayatollah Khomeini to power.

Some of the unrest which followed the revolution hit Britain in the form of the six-day siege at the Iranian embassy in London, which left seven people dead.

Six anti-Khomeini gunmen invaded the embassy on 30 April 1980 and took 26 hostages, among them a police officer and two BBC employees.

As the siege wore on, the men threatened to start killing hostages unless their demands were met.

The SAS stormed the building on the sixth day and shot dead five of the armed men. But two hostages had also been killed by the gunmen.

Rushdie affair

In 1989, Anglo-Iranian relations reached breaking point when British author Salman Rushdie was effectively sentenced to death by Khomeini for his book The Satanic Verses.

Author Salman Rushdie went into hiding after a fatwa called for his death

Khomeini issued a fatwa - or religious ruling - that the novel was blasphemous against Islam and that Muslims had a duty to kill the author.

A bounty was placed on Rushdie's head and the novelist went into hiding with round-the-clock protection.

Tit-for-tat expulsions followed the Rushdie affair and diplomatic relations were suspended for 18 months.

Khomeini died in June 1989, four months after issuing the fatwa.

Slow improvements

Relations between the two countries did improve in 1991 with the release of Terry Waite, who had been held hostage in Lebanon for almost five years.

Iran was perceived as having been instrumental in securing the freedom of Mr Waite, the archbishop of Canterbury's special envoy.

But another row emerged in 1994 when Iran was accused of offering arms and money to the IRA. Iran denied the charge and accused Britain, in turn, of bugging its embassy in London.

A turning point came in 1998 when Iran's government, headed since 1997 by Mohammed Khatami, officially distanced itself from the fatwa on Rushdie.

There followed a deal between Iran and the UK to normalise relations.

However, Iranian hardliners have continued to call for Rushdie's death.

'New rapport'

Last year, the Iranian foreign minister Dr Kamal Kharrazi became the country's first official visitor to Britain since 1979.

Dr Kharrazi met Prime Minister Tony Blair and the then Foreign Secretary Robin Cook.

At the time, Mr Blair's official spokesman said the visit was "about trying to develop a new relationship and rapport".

But he added that the UK remained concerned about human rights issues in Iran.

In February this year, the then UK Cabinet Office Minister Mo Mowlam visited Iran and pledged British co-operation in the country's fight against drug trafficking and addiction.

She praised the "magnificent job" Iran was already doing to stop drugs being smuggled into Europe and Britain and signed a memorandum of understanding with Iran on the drugs issue.