(MENAFN- The Peninsula)
Vienna: Iran's first presence in international talks on Syria underscore a special relationship between the two countries' governments based in part on a joint adherence to the Shiite branch of Islam.
Syrian President Bashar al-Assad and top officials of his regime are members of the country's Alawite minority a Shiite offshoot.
Here is a short history of relations between the two nations since Iran became an Islamic republic.
Support for the nascent Islamic republic
In February-April 1979 the pro-Western shah of Iran is overthrown by a popular revolt and the new leaders declare an Islamic republic.
Already in mid-January a high-ranking Syrian figure had said that Damascus provided direct support for Ayatollah Ruhollah Khomeini against the shah's regime and that relations with the Shiite cleric who went on to found the republic were "excellent".
In 1982 the two countries sign an agreement allowing Syria to buy Iranian crude oil at preferential prices.
A rare Arab backer against Iraq
During the bitter 1980-1988 war between Tehran and Baghdad Syria was one of the only Arab states to side with non-Arab Iran. Libya also backed Iran but in a much more limited fashion.
In September 1990 the 10th anniversary of the war's outbreak then Syrian president Hafez al-Assad paid his first state visit to Tehran since 1979.
In 1997 Tehran said it would support a project to "modernise" Syrian military equipment.
On January 25 2001 the two countries decided to reinforce strategic ties during a visit to Tehran by Bashar al-Assad who succeeded his father as the Syrian leader in 2000.
On January 19-20 2006 then Iranian president Mahmoud Ahmadinejad met in Damascus with radical Palestinian leaders and Hassan Nasrallah head of the powerful Lebanese Shiite militia Hezbollah. Both countries actively back Hezbollah and Assad also voices support for Iran's push for nuclear technology which Tehran says is for purely peaceful purposes.
Tehran is Assad's ally in the Syrian conflict
As early as April 2011 US diplomats accuse Iran of helping Assad's regime repress initial anti-government demonstrations in Syria.
In early 2012 Britain France and the US accuse Iran of shipping weapons to Syria.
In February of that year two Iranian warships visit Syria on a training mission according to local TV.
In April 2013 the head of Hezbollah says it is possible that Iran could intervene directly in the Syrian crisis on behalf of Assad's regime and recognizes that his forces are already engaged in Syria.
Assad acknowledges on September 16 2015 that Iran is providing military and economic support a few months after Syrian lawmakers approved taking a new line of credit from Tehran worth $1.0 billion. Two previous credit lines worth $4.6 billion were set up in 2013.
On October 17 Iran says it will reinforce military advisors sent to help Syria battle "terrorists" after already voicing support for a Russian military operation in the country.
Iran has not officially sent combat troops to Syria but a US official says that up to 2000 Iranians or fighters backed by Tehran have joined a regime offensive against rebels near the second-biggest city Aleppo.
AFP