When war broke out in eastern Ukraine, pilot Nadezhda Savchenko left her hometown to join the fight against Russia-backed separatists. Nearly two years after she was captured, then tried and convicted in Russia, she returned home to a rapturous welcome in Kiev.

Over the past two years, Savchenko became both Ukraine's national hero and Russia's best-known prisoner. Western leaders and diplomats including President Barack Obama called for her release, graffiti supporting her sprouted up and children made drawings romanticizing her image.

Ukrainian President Petro Poroshenko spoke about her case on nearly every trip abroad. When she arrived at a Kiev airport on Wednesday after being swapped for two Russian servicemen who had been imprisoned in Ukraine, a throng of journalists and well-wishers converged on her.

"Step back if you want me to say anything. I have spent two years in a small cell," snapped Savchenko, barefoot and wearing a T-shirt emblazoned with Ukraine's national trident.

Savchenko, 35, had an illustrious career in the armed forces including a stint as Ukraine's only female soldier in the peacekeeping forces in Iraq. She graduated from a prestigious air force school in 2009, which until then had been open only to men. But when the war started in April 2014 Savchenko, retired and went to the east to join the Aidar volunteer battalion.

She was captured by rebels in June 2014 amid intense fighting in the Luhansk region. After her capture, which the rebels documented and filmed, she disappeared and then resurfaced in Russian custody. Russian authorities said Savchenko crossed into Russia voluntarily and illegally, disguised as a refugee. But Savchenko says the rebels who captured her spirited her across the border and handed her over.

Russian state media used Savchenko as a poster child for alleged Ukrainian atrocities in the east. Even though there didn't seem to be any solid evidence to prove her involvement in any civilian deaths in the east, prosecutors launched a case charging that she had been a spotter who called in coordinates for a mortar attack that killed two Russian journalists.

At her first public appearance in Russia, Savchenko defiantly said she didn't recognize the authority of the Russian court and prosecutors. She went on several hunger strikes before and during her trial.

Savchenko often appeared in court in a traditional Ukrainian embroidered shirt or in blouses with the Ukrainian coat of arms or other national symbols. Despite the long incarceration, Savchenko has never complained about bad health or prison conditions, unlike her lawyers, but instead focused on using her public appearances as a chance to condemn Russian interference in Ukraine.

The defiance with which the pilot carried herself throughout the detention and the nine-month trial, calling prosecutors names and singing the Ukrainian anthem, turned her in an unrivalled national hero. A poster with her picture and a call for her release has adorned the rostrum at the Ukrainian parliament for months.

In the autumn after her capture, Savchenko was elected a member of the Ukrainian parliament and appointed to the Parliamentary Assembly of the Council of Europe.

The Ukrainian government insisted from the start that Savchenko was a prisoner of war and should be immediately released. That didn't happen because Moscow argued that Savchenko was a dangerous criminal.

While approval ratings plummeted for many Ukrainian politicians who rose to prominence in the 2013-2014 protest movement which ultimately forced President Viktor Yanukovych to flee the country, Savchenko's imprisonment became a universal cause for Ukrainians to rally around. The party of former Prime Minister Yulia Tymoshenko enlisted Savchenko to top their ballot at the 2014 parliamentary election with analysts saying Savchenko's name was a big draw for voters.

"For the whole world and Ukraine, Nadiya embodies the might of Ukraine, strength, a resistance to occupying forces and the immorality which has unfortunately flooded politics," Tymoshenko said Wednesday.

Savchenko has skirted questions about her political ambitions and didn't mention it upon arrival on Wednesday, but Tymoshenko told reporters Savchenko wants to start working right now.

"She asked me: 'Where do I need to be, where do I go to start working,'" Tymoshenko told reporters. "A strong leader has come back home, that's for sure."