PARIS: Russia invaded neighbouring Ukraine early on February 24, sparking the worst conflict in Europe in decades.
Thousands of civilians have been killed in the fighting, which has taken a new turn over the past week as Ukrainian forces drive Russian forces from key eastern towns in a swift, surprise counter-offensive.
February: invasion
Russian President Vladimir Putin announces on February 24, 2022 a "special military operation" to protect the Russian-speaking self-declared separatist republics of Lugansk and Donetsk in the east, whose independence he has just recognised.
He says he wants to "de-Nazify" Ukraine, a former Soviet state, and demands a guarantee it will never join NATO.
A full-scale invasion starts with air and missile strikes on several cities. Ukrainian President Volodymyr Zelensky pledges to stay in Kyiv to lead the resistance.
The West imposes unprecedented sanctions on Russia, which are toughened over time. The EU and US send arms to Ukraine, with the amount of aid pledged by Washington rising into the billions.
March: advances in south but Kyiv holds
Russian troops attack Ukraine's south coast, seizing most of the strategic region of Kherson, crucial for agriculture, and close to the Russian-annexed Crimean peninsula.
Russian troops seek to surround the capital Kyiv and to take Ukraine's second city Kharkiv in the northeast but face fierce resistance.
A month into the fighting, Russia withdraws from the Kyiv area and northern Ukraine to focus on conquering the eastern industrial Donbas region, partly held by separatists, along with the south.
April: war crimes revealed
On April 2 and 3, the corpses of dozens of civilians are found scattered on the street or buried in shallow graves in the Kyiv suburb of Bucha, which Russian forces had occupied, sparking an international outcry.
Similar grisly discoveries follow in other northern towns and Kyiv suburbs.
May: Mariupol falls
Russia besieges and relentlessly bombards the strategic southeastern port city of Mariupol from the start of its invasion.
The city becomes a symbol of the suffering caused by the war, with bodies piling up in the cellars where residents hide out for weeks.
On May 21, Russia announces that it is in full control of the city, after the troops that held out for weeks at a steelworks surrender.
Also in May, Sweden and Finland apply to become members of NATO, fearing they could be future targets of Russian aggression.
June: Donbas battle rages
In June, all eyes are on the Donbas, where Russia harnesses its superior firepower to conquer the city of Severodonetsk after one of the bloodiest battles of the war.
Shortly after they take the neighbouring city of Lysychansk, as Ukraine pleads for more heavy weapons from the West.
July: grain unblocked, gas supplies cut
On July 22, Kyiv and Moscow sign a deal brokered by the UN and Turkey to resume stalled grain exports from Ukraine, Europe's so-called breadbasket, in a bid to relieve a global food crisis caused by Russia's blockade of the country's ports.
The first official shipment of grain since the invasion leaves Odessa with 26,000 tonnes of maize 10 days later.
The breakthrough on grain is overshadowed however by the escalating gas dispute between Russia and Europe.
Russian energy giant Gazprom slashes its supply to Europe through the Nord Stream pipeline before turning off the tap altogether, prompting fears of gas shortages this winter.
August: nuclear fears
In August, concerns mount over the Russian-occupied Zaporizhzhia nuclear power plant in southern Ukraine, with constant shelling of the area raising the spectre of a nuclear disaster.
UN inspectors visit the plant in early September and call for a security zone to be set up around it.
As the US and EU step up their supplies of heavy weapons, Kyiv launches a major offensive to retake the city of Kherson in the south.
September: Russia in retreat in north-east
Two weeks later Ukraine announces that its troops have retaken more than 3,000 square kilometres of terrain in a second, lightning counter-offensive around Kharkiv in the north-east which appears to have caught Russia off guard.
Kyiv says the area recaptured includes part of Izyum district, which sits on a vital supply route for Russian troops.