Key dates since Russian intervention in Syria

Russia one year ago carried out its first air strikes in support of Syrian President Bashar al-Assad's forces, in a major turning point in a multi-sided civil war. A timeline: Start of Russian intervention - September 30, 2015: Russia, at the Damascus regime's request, launches air strikes on Syria, saying it has hit Islamic State (IS) targets. Russian President Vladimir Putin says Moscow must act preemptively to destroy jihadists in Syria before they present a threat closer to home. Syrian rebels and their overseas supporters accuse Moscow of targeting mostly non-jihadist groups to come to the aid of the Syrian army, which had suffered a series of resounding defeats since March 2015. Air strikes intensify - October 7, 2015: Russia's defence ministry says that for the first time Russian warships in the Caspian Sea fleet joined in strikes in Syria with a volley of 26 cruise missile attacks against 11 targets in Syria. - December 9, 2015: The Russian army strikes Syria from a submarine deployed in the Mediterranean. Diplomatic offensive - October 20, 2015: Putin launches a diplomatic initiative and invites Assad to Moscow for a high-profile visit -- his first official trip abroad since Syria's conflict erupted in March 2011. - From October 23, 2015: The US, Russian, Saudi and Turkish foreign ministers hold unprecedented talks in Vienna to try to find a way out of the Syrian crisis. - November 14, 2015: After a first meeting on October 30, the big powers, including Russia, the United States, France, and for the first time Iran meet in Vienna where they agree on a fixed calendar for Syria but remain sharply at odds over the future of Assad. Regime forces retake territory - February 1, 2016: Syrian regime forces, backed by Russian air strikes, launch an offensive against rebels around the northern city of Aleppo. Rebels lose stronghold after stronghold. - March 15, 2016: Russia's Putin announces a partial withdrawal of Moscow's forces from Syria which is widely publicised despite lack of details of how much of the contingent remains. - March 27, 2016: The Syrian army, backed by its Russian ally, retakes the ancient city of Palmyra from IS. - June 18, 2016: Russian Defence Minister Sergei Shoigu meets with Assad in Damascus to discuss anti-terrorist "cooperation" and inspects Russia's air base in Hmeimim in the Syrian coastal province of Latakia. Russia-Turkey reconciliation - August 9, 2016: Turkish President Recep Tayyip Erdogan, whose country backs the Syrian rebels, meets Putin in St Petersburg in a bid to heal ties, strained by the Syria conflict. Tensions had soared in November 2015 between the two rival players in the Syria war when Turkey shot down a Russian warplane on the Syrian border, saying it had violated its airspace. First strikes from Iran - August 16, 2016: Russia says its warplanes flew out of an Iranian airbase for the first time to bomb jihadist groups in Syria. - September 21, 2016: Shoigu says that Moscow is dispatching its flagship aircraft carrier to bolster its forces in the eastern Mediterranean off Syria. The announcement comes as a new truce reached on September 9 between Moscow and Washington collapses after being in force for only a week. Blitz of Aleppo - September 22, 2016: The Syrian army announces a major offensive aimed at retaking rebel zones in Aleppo. The rebel-held east of Aleppo has since come under a deadly bombardment by the regime and Russian airstrikes. Moscow and Washington have traded blame over the truce's collapse, amid heavy international criticism of Russia's participation in the Aleppo offensive.