The Christmas tree spat began in 2010, when Latvians started an advertising campaign that claimed that Riga was the first, citing 1510 as the year when a mysterious and rambunctious medieval brotherhood known as the House of the Black Heads paraded through Riga carrying a constructed replica of a tree. They decorated it with fruits and candles, danced around it and then, a few days later, burned it to the ground.
Hold on a second, responded the Estonians. They produced evidence that they claim showed that a similar festival had taken place at yet another lodge of the Black Heads, this one in Tallinn in 1441.
And their festival, Estonians claim, involved a real tree. In fact, said the historian Juri Kuuskemaa, “we can be sure it was a spruce.”
Riga’s mayor, Nils Usakovs, countered that claim by saying that the Estonians employ post-truth tactics when it comes to the invention of the Christmas tree.
It’s an unusual war, fought with ornaments and historians.
“Cities like Berlin had to wait until the 18th century before the first recorded public use of a Christmas tree,” sniffed Mr. Kuuskemaa, 74, who is also the official Herald of Tallinn, a ceremonial position for which he often dons period garb. “And for Paris and London, it didn’t happen until the 19th century. Tallinn and Riga did it centuries before all the great metropolises of Europe.”
Whizzing round the capital the week before Christmas, Mayor Usakovs has taken on the work ethic of an elf. At the foot of a former landfill site that is being converted into a miniature ski resort, Mr. Usakovs lit his 48th Christmas tree of the season.
He said the Christmas tree conflict, in reality, had reached a bit of a historical stalemate, as there was not enough contextual evidence to say for certain which city came first. But he doesn’t care.
“Any time they say they were first, they have to mention also our city,” he said. “Tourists from Germany or Belgium or Russia don’t care for historical truth; they care about cities with fancy Christmas trees, fancy Christmas markets. And when they read that there is also this battle between Tallinn and Riga — it’s fun!”
Nearly 200 miles north, in Tallinn, the chairman of the Estonian Parliament’s defense committee, Hannes Hanso, stood beside the official parliamentary tree and declared that he took a policy of total nonrecognition when it came to Riga’s claims.
“I didn’t know Latvia had any claim to the first Christmas tree,” he said with mock incredulity.
Mr. Hanso also reminded Latvians not to get any ideas about who has the highest mountain either, as Estonia’s Big Egg Mountain, at 1,043 feet, was clearly higher than Latvia’s Gaizinkalns, which reaches to a mere 1,024 feet.
Deployments of elves and reindeer have become the important weapons for Baltic nations to keep tourism levels steady over an otherwise dead season. It is especially important for Latvia and Estonia where, according to the World Travel and Tourism Council, tourism’s direct contribution to gross domestic product is twice as big as it is in Lithuania, the southernmost Baltic state. In 2015, in Lithuania it amounted to 1.7 percent, whereas in Latvia and Estonia it was 4.1 percent and 3.9 percent.
With the weak ruble keeping many Russian tourists at home, Christmas profits are even more under threat. The Russian Orthodox Church celebrates the birth of Jesus in early January, so the holiday markets could stay open for weeks longer and still find eager crowds.
Mariann Lugus, secretary general of the Estonian Travel and Tourism Association, said that Estonia had detected a dip in the number of Russian tourists in January 2014. A year later, though, after the Russian seizure of Crimea and the imposition of international sanctions, Russian tourism plummeted. Only about half as many Russians visited that January.
Latvia, for some reason, has not experienced similar drops. “We don’t know why that is,” said Irena Riekstina, secretary general of the Association of Latvian Travel Agents and Tour Operators. “This is probably going to happen at some point and we need to prepare for this.”
Maximilien Lejeune, executive director at European Best Destinations, a travel website, said that the Christmas tree war could end up attracting even more visitors to both cities as they compete for other popular Christmas season destinations like Lapland and Norway — especially if tourists become nervous about attending holiday markets in cities that have experienced terrorist attacks.
Keen to compete is Remigijus Simasius, the mayor of Vilnius, the capital of Lithuania. Though his city has no claim to the first Christmas tree, he hopes to compete with even larger and more elaborate presentations.
He threw down the gauntlet this year with a towering tree adorned with 50,000 bulbs, which drew wide acclaim. His tree provoked rebukes from Russia, though, where several articles accused the Lithuanians of copying the tree’s design from a smaller one in Moscow’s Red Square.
Lithuania may have no claim to the first Christmas tree, Mr. Simasius said in his annual Christmas speech, but it was important to think in broader terms.
“We are part of the Baltic Sea region, and we are happy that this tradition is born in our region,” he said.
Mr. Lejeune said that “in troubled times, people like to have landmarks,” and that’s what European holiday markets have become.
“People also like to escape when the news makes them afraid,” he said. “That’s why magic movies have such success in cinemas. The Christmas markets also allow people to escape a bit from reality.”
But not everyone is in the Christmas spirit. Gustavs Strenga, an archivist and historian at the National Library of Latvia, said that both Riga and Tallinn were guilty of making creative leaps with their historical interpretations.
Actually, he said, those tree-themed celebrations by the Black Heads had nothing to do with Christmas and were connected to other festivities the brotherhood celebrated.
Looking down at his coffee cup, Mr. Strenga admitted that his skeptical position had not gone down well in Latvia.
“I’ve been called the Grinch,” he said.