Hundreds of ancient artifacts from Crimea that were stored in a Dutch museum for nine years while Russia and Ukraine waged a legal battle over their ownership are now back in Ukraine, officials in Amsterdam said on Monday.

The works arrived on Sunday at the Museum of Historical Treasures of Ukraine in Kyiv, said officials at the Allard Pierson Museum, an archaeological museum at the University of Amsterdam, which borrowed around 400 works from four Crimean museums in 2014 for the exhibition “Crimea: Gold and Secrets of the Black Sea.” The artifacts included gold jewelry, gold plaques, precious gems, Greek and Roman stone ornaments and ceramics.

A month into the show’s run, Russia annexed the Crimean Peninsula, and when it came time to send the objects back, a legal conflict emerged: Should they go back to the Crimean museums, now under Russian state control, or to Ukraine, which argued that the works were part of its national heritage?

The nine-year struggle over the treasures became a kind of proxy war over national sovereignty and cultural property. Els van der Plas, the director of the Allard Pierson Museum, said in a statement that it was “a special case in which cultural heritage became a victim of geopolitical developments.”

Rostyslav Karandeev, Ukraine’s culture minister, announced the return of the objects last Tuesday in a statement on a government website, expressing gratitude to the museum for storing them while the dispute was ongoing.

But the University of Amsterdam declined to confirm the Ukrainian announcement last week. Yasha Lange, a university spokesman, said on Monday that the university had remained silent because the gold was still in transit. Now that it was securely in Kyiv, he said, “We’re happy that these objects are now returned to their legitimate owners.”

Russia’s 2014 annexation of Crimea was President Vladimir V. Putin’s first major incursion into Ukrainian territory, a move that the United Nations said was illegal and that the European Union strongly condemned. Russia escalated its attack on Ukraine in February 2022 with a full-scale invasion that has seen the destruction of cultural sites and the looting of artifacts from Ukrainian museums.

Ukraine’s culture ministry had argued that the Crimean treasures should be transferred to Kyiv because they were owned by Ukraine at the time of the exhibition, and were in danger of being seized by Russia if returned to Crimea.

The four lending museums — the Central Museum of Tavrida, the Kerch Historical and Cultural Preserve, the Bakhchisaray History and Cultural State Preserve of the Republic of Crimea and the National Preserve of Tauric Chersonesos — argued that the objects should be returned to them based on the loan agreements.

At a news conference on Monday, Dmitry S. Peskov, the Kremlin spokesman, reaffirmed Russia’s longstanding position that the collection should return to those museums. “It belongs to Crimea and must be there,” he told reporters at a news conference, according to Interfax, a Russian news agency.

President Volodymyr Zelensky of Ukraine praised the Dutch Supreme Court’s ruling in June, writing on X, formerly Twitter, that the collection “cannot be returned to Crimea for an obvious reason — it cannot be given to the occupier, the robber.” He vowed to return the works to their places of origin at a future time when he hoped that Ukraine would reclaim the territory. “Of course, it will be in Crimea,” he said, “when the Ukrainian flag will be in Crimea.”

Because of the fragility and value of the objects — around $1.5 million, according to court documents — preparations for their return took several months, Mr. Lange said. The Allard Pierson Museum had agreed not to charge Ukraine for nine years of storage fees while the treasures were kept in its basement, including security and climate control costs, he said, adding that Ukraine had covered some moving costs.

“At the end of the day, we felt this was the right thing to do,” Mr. Lange said. “Nobody wished for this to be the situation.”

Ivan Nechepurenko contributed reporting from Tbilisi, Georgia.