General Valery Zaluzhny, who led the Ukrainian army throughout Russia's invasion, is revered by many Ukrainians as the man who thwarted Moscow's plan to seize Kyiv.
While he has avoided the political spotlight, Zaluzhny is credited with spearheading some of Ukraine's most successful battles against Russia, including the liberation of Kherson city in November 2022.
But the failure of a much-vaunted counter-offensive last year and public disagreement with Ukrainian leader Volodymyr Zelensky has tarnished his reputation in the president's office.
After weeks of swirling rumours, Zelensky finally dismissed Zaluzhny on Thursday.
Speaking immediately after, Zaluzhny conceded Ukraine's strategy should change, almost two years into Russia's invasion.
"The tasks of 2022 are different from those of 2024. Therefore, everyone must change and adapt to the new realities as well. In order to win together," he said.
In November 2023, Zaluzhny told The Economist that the conflict with Russia was at a "stalemate" and there would "most likely be no deep and beautiful breakthrough", an admission that Zelensky flatly denied.
In an opinion piece for CNN three months later, the 50-year-old said the army was bogged down by "regulatory framework" and called for urgent modernisation.
Zaluzhny said Ukraine's army could not grow unless lawmakers took "unpopular" measures to mobilise more men, a highly contentious issue in Ukraine and a measure that Zelensky has been reluctant to implement.
His public comments -- mainly to Western news outlets -- have been a source of constant consternation for Zelensky, already struggling to maintain unity amid infighting in Ukraine's parliament.
And while Zaluzhny did not explicitly mention Zelensky by name, reports of a deepening rift between the two continued to swirl.
The commander came to symbolise Ukraine's defiance and has become one of the country's most popular figures, according to several opinion polls.
Media reports said this popularity may have sparked jealousy from Zelensky's entourage.
Ukrainians credited Zaluzhny with the failure of an initial Russian plan to take Kyiv and for the successful offensives in late 2022 in which Ukrainian troops took back large swathes of territory.
Russia's plans for a "Blitzkrieg, a change of power and of Ukraine's geopolitical orientation have been ruined", Zaluzhny wrote on Facebook two weeks after the start of the invasion.
"No matter how difficult it is for us, (this war) will certainly not bring shame on us," he wrote.
In 2022, the Ukrainian edition of Vogue magazine carried an article about Zaluzhny, calling him "a legendary figure". TIME magazine named him as one of the 100 most influential people in the world alongside Zelensky.
Zaluzhny was born on July 8, 1973 at a Soviet military base in Novograd-Volynsky in northwest Ukraine.
He has been in the military for 24 years.
When Russia-backed separatists began seizing territory in eastern Ukraine in 2014, he helped lead operations to fight back.
Named head of the military's northern command in 2019, he was promoted to commander-in-chief of Ukraine's armed forces in July 2021 by Zelensky.
The general prioritised reforms in the army to meet the standards of the NATO military alliance which Ukraine wants to join despite Russia's opposition.
A few months later, in a rare interview, he warned about "the threat of a major aggression" by Moscow.
"We have to prepare for it," said Zaluzhny, a father of two daughters including one serving in the military.
Underlining his role as a member of a younger generation of officers with combat experience against the separatists, he called on Ukraine's military command to "use all means" to "preserve the life and health" of soldiers.
Despite his popularity, Zaluzhny has never signalled any political ambition and his public pronouncements are rare.
