Ukrainian President Volodymyr Zelensky today echoed Winston Churchill and William Shakespeare in a historic address to the House of Commons.
The heroic leader praised Boris Johnson but demanded a no-fly zone as he declared: "We will fight to the end."
Zelensky received a standing ovation as he addressed MPs at Westminster, via videolink and through a translator, as his country continued to face a barrage of Russian attacks.
He listed a devastating day-by-day rundown of Russia's actions in its invasion of Ukraine, from killing 50 children to bombing hospitals and leaving those in Mariupol running out of food.
He closed by saying: "The question for us now is to be or not to be - the Shakespearean question. For 13 days this question could have been asked but now I can get you a definitive answer. It’s definitely yes, to be."
Zelensky - who has survived three assassination attempts - gave his address live from Ukraine, where it was strictly time-limited to prevent Russians tracking his signal.
Echoing Winston Churchill's Second World War vow to "fight on the beaches" - made in the same chamber 82 years ago - he went on: "We will not give up and we will not lose. We will fight to the end at sea, in the air.
"We will continue fighting for our land whatever the cost. We will fight in the forests, in the fields, on the shores, in the streets."
He said he was "very grateful" to Boris Johnson but made another plea for a no-fly zone - which the West have already rejected, for fear of escalating into a war between 30 NATO countries and nuclear-armed Russia.
Zelensky said: "Please increase the pressure of sanctions against this country (Russia), and please recognise this country as a terrorist state - and please make sure our Ukrainian skies are safe.
"Please make sure that you do what needs to be done and what is stipulated by the greatness of your country.
"Glory to Ukraine and glory to the United Kingdom."
Commons Speaker Sir Lindsay Hoyle granted the Ukrainian leader's historic request - with large screens being installed in the chamber. It is thought to be unprecedented, with addresses to Parliament usually happening in nearby Westminster Hall not the chamber.
It came days after an address by Zelensky to the European Parliament, where he raised his fist and declared glory to Ukraine, received a standing ovation.
The Ukrainian Ambassador was in the gallery of the packed Commons chamber where MPs wore yellow ties and crammed in to sit on steps.
Boris Johnson was flanked by Liz Truss and Priti Patel, with Ben Wallace next to her. Keir Starmer was flanked by Angela Rayner and David Lammy.
Responding to Ukraine's President, Boris Johnson said: "Never before in all our centuries of our Parliamentary democracy has the house listened to such an address.
"In a great European capital now within range of Russian guns, President Zelensky is standing firm for democracy and for freedom.
"In his righteous defence I believe he has moved the hearts of everyone in this House. At this moment ordinary Ukrainians are defending their homes and families against a brutal assault.
"They are by their actions inspiring millions by their courage and their devotion. This is a moment for us to put our political differences aside."
The PM vowed to "press on with tightening the economic vice around Russia", adding: "We will employ every method we can, diplomatic, humanitarian and economic until Vladimir Putin has failed in his disastrous venture and Ukraine is freed once more."
Labour leader Keir Starmer said: "Every one of us has been moved by the bravery, resolve and leadership of President Zelensky.
"Invading troops march through his streets, shells rain down on his people and assassins seek his life. No one would have blamed him for fleeing. But instead he has stayed in Kyiv to lead the Ukranian people and to fight
"He's reminded us that our freedom and democracy are invaluable. He's prompted the world into action."
Lib Dem leader Sir Ed Davey called for Zelensky to get a knighthood.
Boris Johnson, who speaks almost daily with Mr Zelensky, earlier hosted meetings with the leaders of the 'Visegrad Four' Poland, Hungary, Slovakia and the Czech Republic.
He spoke on Monday night with US President Joe Biden and the leaders of France and Germany, all vowing to continue to applypressure on Russia and to isolate Vladimir Putin's regime.
Today the UK announced it would phase out imports of Russian oil by the end of the year, but not Russian gas.
Britain also appointed a dedicated minister for refugees after granting just 500 visas to Ukrainian family members since Friday.
Mr Zelensky, a former actor who played an accidental President in a 2015 comedy, has been the figurehead of Ukraine's struggle since Putin's forces invaded the country last month.
Justice Secretary Dominic Raab will travel to The Hague to bolster efforts to gather war crimes evidence against Vladimir Putin's regime over Ukraine.
The Deputy Prime Minister, a lawyer who has a background in prosecuting war crimes, will liaise with the International Criminal Court on potential war crimes Russia may have committed during its invasion.
The ICC has already started an investigation that could target senior officials believed to be responsible for war crimes, crimes against humanity or genocide.
Speaking to MPs, Zelensky said: "Mr Speaker, all the Members of Parliament, ladies and gentlemen, I am addressing all the people of the United Kingdom and all the people from the country with a big history.
"I am addressing you as a citizen, as a president, of also a big country, with a dream and big effort.
"I would like to tell you about the 13 days of war, the war that we didn't start and we didn't want. However we have to conduct this war, we do not want to lose what we have, what is ours, our country Ukraine."
Zelensky ran day-by-day through the war so far, saying on Day 4 Ukrainians started capturing Russian soldiers but "we have not been torturing them. We remained humane even on Day 4 of this terrible war."
He went on: "On Day 11 the children and cities were being hit, and hospitals as well with their rockets and constant shelling."
On Day 13 in the city of Mariupol, he said, “a child was killed. They do not allow any food, any water and people started panicking... people do not have water over there, over 13 days of this situation over 50 children have been killed.
"These are the children that could have lived - but these people have taken them away from us."
