Aleksandar Vucic’s crushing election defeat by a student-backed protest movement has cast gloom over Moscow, which has lost another important partner in Europe just six months after ally Viktor Orban was ousted in an election in Hungary.

Serbia woke to a new era on Monday after Vucic, a frequent visitor to Moscow who had been prime minister or president since 2014, suffered a defeat on Sunday that prompted nationwide celebrations, although few had any idea of how the Balkan country’s new student-backed leaders would govern.

Russia saw Vucic’s Serbia as a crucial ally in Europe, and as a bulwark against what Moscow has cast as the European Union’s aggressive attempts to contain and punish it over its war in Ukraine.