Here is the official Twitter account of the country of Ukraine, insulting the Russian government by way of a Simpsons GIF:

The tweet, from Tuesday morning, is amazing on its own. Two countries that have functionally been at actual, physical war for about three years feuding on Twitter — using a GIF from The Simpsons, no less.

But it’s also kind of confusing out of context. Ukraine didn’t just randomly wake up and decide to insult Russia on Twitter. Instead, its leaders were actually responding to an insult from Russian President Vladimir Putin himself.

The meaning of the fight

Putin was in Paris on Monday, to meet with French President Emmanuel Macron. The meeting was awkward. Russian propaganda outlets backed Macron’s opponent, far-right populist Marine Le Pen; hackers seemingly aligned with Russia hacked Macron’s emails and dumped them publicly. Indeed, Macron specifically went after two Russian state-run media outlets, RT and Sputnik, in his comments, attacking them as “deceitful propaganda.”

But for Ukrainians, the meeting was upsetting for a different reason. During Putin’s opening remarks, he dated the French-Russian friendship back to the 11th century, specifically a French queen from eastern Europe named Anne. Putin described her as “Russian Ani,” pointing to her a symbol of cooperation between the two countries.

Except Putin left something out. Anne is best known as Anne of Kiev — Kiev being both her hometown and the current capital of Ukraine (now spelled Kyiv).

At the time, Kiev was the capital of a country called Kievan Rus, which covered bits of territory from a number of different countries in the area (including contemporary Ukraine and Russia). By claiming Anne for Russia, Putin appeared to be claiming all of this shared history for Russia exclusively — and Ukrainians were not pleased.

“My dear French friends, Russian President Putin tried to mislead you today,” Dmytro Shymkiv, a Ukrainian official who works on digital issues, wrote on Facebook shortly after the comments. “Moscow did not even [exist] by that time.”

Ukraine’s official Twitter account followed Shymkiv’s line almost directly in its first post on Tuesday morning — trolling Putin by pointing out that Moscow didn’t exist, so it doesn’t make sense to call Anne Russian:

When @Russia says Anne de Kiev established Russia-France relations, let us remind the sequence of events pic.twitter.com/nBKhQdyKql — Ukraine / Україна (@Ukraine) May 30, 2017

Russia responded by claiming the comment was meant to unite Ukraine and Russia (and Belarus, the third flag in the following tweet) by celebrating their shared heritage. It also pointed out the Anne-era accomplishments of another Kievan Rus city that is currently part of Russia:

@Ukraine We are proud of our common history. , & share the same historical heritage which should unite our nations, not divide us. pic.twitter.com/hdmkuGy22p — РоссиЯ (@Russia) May 30, 2017

Ukraine, of course, saw this as a fig leaf for annexing Ukrainian history in the same way that Russia has literally annexed part of Eastern Ukraine.

Hence why it responded with the now-famous Simpsons GIF tweet, comparing Putin’s Russia to the Soviet Union (which notably annexed all of Ukraine):

And now you are up to speed on two warring nations’ Tuesday morning Twitter beef.