Angela,
ROCOR stands for Russian Orthodox Church Outside of Russia. When the Russian revolution broke out, the Bolsheviks took over the government in 1917. I leave it to the more educated here to explain those details. What I will say is that there was great persecution against the Holy Russian Church and Patriarch Tikhon was killed for it because he refused to bow down to their anti-Christian takeover. As a result, Pat. Sergei, of sorrowful memory, did the deed when he was elected by the atheistic, communist government that took control. These atheists also killed the Tsar family. If you google these references, you will find plenty of information.
So, it became a time of preserving Orthodoxy against the atheist regime. You must have heard about how communists treated the Orthodox? The Greeks also had to face the same persecution. One day, your Greek Orthodox neighbor is your friend and the next day, he is spouting communist propaganda and turning you over to the communists for whispering a word of discontent about the way things are run by the communists. You would be at risk of being taken to a secluded area and shot in the head. Have you seen the movie, ELENI?
Back to Russia.... Churches were destroyed. Holy Altars were descecrated. Crosses from the church tops were torn down. Everybody lived in fear that the police would break down their doors and round them up because someone mentioned that he saw an icon in their house. Many parents and children were seperated, never to see each other again or many saw their parents or children killed in front of them. Whole villages were starved to death. People were taken out in the streets and tortured to death to make an example to others.
Anyone who was arrested and taken to court was quickly convicted. Many were killed and others were sent to Gulags(concentration camps), where many died.
Bishops and priests were arrested AND killed, with no trial, because they would not pledge their faith to the government but to Christ; they were shaved and stripped and tortured. The communist government wanted to replace the authority of God in the church and Pat. Sergei, of sorrowful memory was the one that accepted it.
But, there were some bishops that were able to escape. Again, I leave it to those with knowledge to explain the details.
They left their beloved homeland and dispersed to different countries. They seperated their communion with the false Patriarch and established a community outside of Russia. They preserved their love for Orthodoxy and faith in Christ. Over time, ROCOR established a strong body of faithful who resisted the Moscow Patriarchate(MP).
And now, with sorrow in our hearts...the bishops of ROCOR, have decided to re-establish their communion with the MP(but they call themselves the Russian Orthodox Church).
The MP are so deeply involved with the WCC and ecumenism. It is not right to join with them now...but apparently, most of the ROCOR bishops are either complete idiots or have been groomed to think without an Orthodox conscience.
There are plenty more details but you will need to take time to absorb them.
Joanna