On Wednesday it was reported the subject would be mandatory for schools in Russia's Belgorod, Kaluga, Bryansk and Smolensk regions, and optional for another 11 regions, despite protests from secular officials.
"I believe the basics of Orthodox culture is a culturological subject, and all young people studying at school should know the history of their culture," Patriarch Alexy II of Moscow and All Russia told journalists at the State History Museum following the opening of an exhibition dedicated to Russian patriarchs.
Alexy II said all cultured people should know their state's history and the basics of its culture.
"If people practicing other religions live in our country, they should study their culture, of course, but they should also know the culture of the country they live in," the patriarch said.
Orthodox leaders have long pressed for a course on the history of Christianity, whether optional or mandatory, to be included in school curriculums. Leaders of other faiths practiced in Russia, however, said a course on the history of all religions should be introduced.
Advocates of a secular society have protested the introduction of such a course in schools at all, saying that even if students were interested and it was introduced, it would have to be taught by secular professors and be optional rather than mandatory.
According to polls, a majority of Russians practice Orthodox Christianity, although the church is separate from the state.