The Donetsk and Lugansk regions are located in what is known as the Donbass Basin in eastern Ukraine. The rift has begun to widen between Kiev on the one hand and the two regions and a number of other regions on the other hand, after the 2014 revolution that toppled President Viktor Yanukovych from Donetsk.
The population there - most of whom are Russian-speaking - refused to recognize the new authority, and after a wave of refusal, protesters took control of government headquarters and institutions, and announced the establishment of what they described as the Donetsk and Lugansk people's republics, based on a public referendum on secession.
No country has recognized this declaration, but the Minsk Agreement signed in 2015 stipulated that they would remain in Ukraine while giving them a special legal status that protected their core security and political interests.
Russia did not hide its humanitarian, moral, political and economic support for Donetsk and Luhansk, and granted about 700,000 of its residents Russian citizenship.
In its latest escalation on Ukraine's borders, Moscow says the residents of the two regions are being persecuted by Kiev, and accuses it of violating the Minsk Agreement.
And the story of the breakaway regions and the unilateral proclamation of republics did not begin only in Russia's neighbourhood.
In 2008, Moscow recognized Abkhazia and South Ossetia after they separated from Georgia, following an armed conflict in which Moscow supported the separatists.
On Monday evening, Russian President Vladimir Putin announced his country's recognition of the independence of the separatist regions of Ukraine, Donetsk and Luhansk, and signed two decrees recognizing Russia's two republics, asking the Russian parliament to immediately recognize this decision.
Russian media reported that two military convoys headed to the two regions to ensure peace, as Moscow says.
While the European Union - through its High Commissioner for Foreign Policy Josep Borrell - considered that Putin's dispatch of peacekeeping forces to Donetsk and Luhansk is an outright aggression against Ukraine, and a violation of its territorial integrity and sovereignty.