The European Court of Human Rights said Tuesday that Turkey violated the free speech of a top opposition figure who was convicted over criticism of Recep Tayyip Erdogan eight years ago.
Erdogan, then serving as prime minister, was criticised over a Turkish air force bombing as well as a controversial hydroelectric dam.
He sued Kilicdaroglu and won, with a court setting heavy fines that critics said were intended to discourage other opponents from speaking out against the government.
But the European court said the Turkish judges "failed to examine the offending remarks within the context and the form in which they had been made."
"Mr Kilicdaroglu had given the speeches as a member of parliament," it added, and as head of the main opposition Republican People's Party (CHP).
"In this connection the court reiterated that, while being precious for everyone, freedom of expression was particularly important for an elected representative of the people."
Kilicdaroglu has repeatedly crossed swords with Erdogan since, in particular after the president's crackdown on opposition parties in the wake of a failed 2016 coup.
The European court ordered Turkey to pay Kilicdaroglu some 13,000 euros ($15,400) in damages and legal costs.
The seven judges who heard the case, including one from Turkey, gave a unanimous ruling, though the Turkish judge dissented on the awarding of damages.
Turkey, though not a member of the European Union, falls under the jurisdiction of the ECHR as a member of the Council of Europe, the continent's leading human rights organisation, since 1950.