The key events in the battle for Bakhmut, the war’s longest-running sustained fight.

The city of Bakhmut has been the center of fighting in the Donbas region of eastern Ukraine for months, and the site of one of the longest and deadliest battles of the war.

Here’s a look at how the battle has played out:

When two Ukrainian cities in the Lugansk region of eastern Ukraine fell to Russian forces in quick succession last summer, Bakhmut, a city about 30 miles to the southwest, became the next target of Russia’s campaign. to secure the entire Donbas.

Bakhmut had been a supply center for Ukrainian fighters in the two cities of Luhansk, Sievierodonetsk and Lysychansk, and had been repeatedly shelled by Russian forces, causing much of Bakhmut’s population of about 70,000 to flee. . At the time, however, few expected the city, which was also the site of fierce fighting in 2014, to become the longest sustained battle of the war.

Russia’s assault on Bakhmut was based on tactics employed in previous battles: deploying artillery firepower and attempting to take neighboring towns and villages before moving into the city itself.

At the same time, Moscow, which generally controlled territory to the east of the city, cut off supply routes to Bakhmut that were being used by Ukrainian forces. Cutting off that access would force Ukrainian forces to withdraw to avoid being encircled.

In the fall, the two sides fought close together, and the shelling of the city intensified.

In a national address, President Volodymyr Zelensky of Ukraine accused Russia of turning Bakhmut into “burned ruins.” Among Ukrainians, the phrase “keep Bakhmut” became a rallying cry, and the defense of the city increasingly became a national symbol of resistance.

Russian forces captured the town of Klishchiivka, south of Bakhmut. Ukrainian forces had considered it key to the defense of Bakhmut because the town lies on high ground to the east of the roads leading into the town that were crucial for resupplying the forces defending the town.

Ukrainian forces withdrew from the town of Soledar, northeast of Bakhmut, allowing Russian forces to tighten their grip near the town. Russia later claimed to have taken a handful of villages near Soledar, further endangering resupply routes to Bakhmut.

The situation became dire for the Ukrainians, with their main remaining supply route, which one general called the “last breathing tube”, coming under increasing attack by Russian forces. A US intelligence assessment at the time, leaked online in April, said that as of February 25, Ukrainian forces in the city “were almost operationally surrounded.”

Zelensky told the Ukrainians that “the situation is becoming more and more difficult,” and the Ukrainian military barred aid workers and other civilians from entering Bakhmut for security reasons, a decision seen as a prelude to a possible withdrawal.

But Ukraine sent reinforcements, including a variety of elite units, and managed to push back the Russian forces enough to allow the resupply of soldiers in the city and the evacuation of the wounded.

The commander of Ukraine’s ground forces, Colonel General Oleksandr Syrsky, twice visited the soldiers in Bakhmut and said that Russia was bringing its “most ready units” into combat.

Wagner’s mercenary force, which helped lead the Russian assault on the city, seized control of most of eastern Bakhmut, leaving the Bakhmutka River, which runs north-south through the center of the city, as the new front line Yevgeny V. Prigozhin, the founder of the Wagner group, said: “The pincers are closing.”

In fierce urban combat, Ukrainian forces defended a western part of the city that was only 20 blocks wide, constantly shrinking and relentlessly pounded by artillery.

Russia intensified its attacks on Bakhmut with artillery and airstrikes, Ukraine said, even as Kiev’s forces struggled to maintain control of vital roads leading west out of the city, their last major resupply and evacuation route.

Mr. Prigozhin threatened to withdraw his fighters from Bakhmut on May 10 due to a lack of support from the Russian Defense Ministry, but appeared to back down two days later, saying he had been promised as much ammunition and weapons as necessary. to continue the fight.

In mid-May, Ukrainian forces managed to recapture some of the territory to the north and south of Bakhmut, even as Russian forces continued their assault inside the city limits.

On Saturday, Prigozhin claimed that the city was fully under Wagner’s control, a claim Ukrainian authorities quickly rejected. Hours later, Russia’s Defense Ministry said the capture of the city “has been completed.”