In Lithuania, the Orthodox faith is perhaps even more ethnic than Judaism. That is, the vast majority of Lithuania’s Orthodox population is ethnically Slavic, primarily Russian. This is in stark contrast to Latvia, Estonia or Finland where there are many Orthodox people of titular ethnicity. Interestingly, a separate Lithuanian Orthodox Church doesn’t even exist. All the Orthodox Church buildings are directly subordinated to the Russian Orthodox Church based in Moscow.
Vilnius, for centuries the capital of multi-religious Grand Duchy of Lithuania, had Orthodox churches since the 14th century. But this faith came to the other parts of Lithuania only after the annexation by the Russian Empire in 1795. Czarist policy of Russification brought large domed churches to the new wide squares and straight avenues, and so even today in Vilnius 19th century districts the Orthodox churches outnumber the Roman Catholic ones. Every major town of the 19th century Lithuania received its own Orthodox church (more than a single one in Vilnius and Kaunas). A minority of these buildings were ceded to the Roman Catholic community after the 1918 independence, but the iconic neo-Byzantine facades and domes remained intact even there.
In an Orthodox church, you may feel as being suddenly transferred to a land further east because there are usually no Lithuanian words whatsoever. Even signs for tourists are typically available only in Russian and English. Website of the Orthodox Church in Lithuania lacks any non-Russian version.
The bond between the Russian nation and the Orthodox church continued well into 20th century. Even the anti-religious Soviets had preferential treatment of the Orthodox church in Lithuania. Under the Soviet rule, a large number of Catholic churches were closed down, whereas almost every Orthodox church remained open. Thus there was an equal number of open Catholic and Orthodox churches in Soviet Vilnius even though Catholic devotees outnumbered Orthodox ones by 10 to 1. The only monastery permitted to operate in Lithuania after the Soviets disbanded all the others was the Russian Orthodox Holy Spirit monastery in Vilnius.
There are 43 Orthodox churches in Lithuania with the most interesting being in Vilnius. 4,6% follow the faith.