Earlier I mentioned that you might think a person to be Polish but discover a person had a Ruthenian, Ukrainian, or other ethnic identity. You may also discover in your search for archival documents that there are religious records and duplicates called "city" or "town" records - Civil Records. You may notice the start date on these is about 1860 - compliance was not immediate. What happened is that Priests were told to make duplicates of parish records of births, marriages, and deaths to be submitted to government so then these second sets got called Civil. It's a good thing because two handwritten copies meant more survived. However, I've noticed the year dates are not always the same between church and civil as if some records were lost. You may have to look at both.
I recently had an experience that made me question previous research that went to a date I was seeking for a baptismal. Not finding it, I decided to read every page of marriages, taking notes by hand. And there I found a selection of dates out of order. However, sometimes the civil copies are more readable since an effort was being made to copy.
Some collections are clearly from Roman Catholic parishes and others are clearly Greek Catholic. Also called Eastern Orthodox, in archives and databases I see "Greek." Generally there was an implied ethnic difference in religion. Ruthenians tended to be Greek Catholics or Uniates (accepting the Roman Catholic Pope but following their own rituals, saints, and calendar). They also tended to be living closer to the Carpathian Mountains or where the eastern part of Poland was, about where Ukraine is now.***
But take the following into consideration:
Ruthenians had three sub-ethnic groups or tribes within their ethnicity. The most familiar to us today are the Lemko and if you're looking at records for Village up close to mountains or mountain passes. they are probably Lemko.***
Then, the Ruthenian people had their own language but back in the day when few people went to school - girls were often not sent at all even when their family had means - just about everyone was multilingual, especially because these were Slavic languages and had many similarities, they could understand each other. (German would be the most popular language after the Slavic.) In market and trade towns very many languages were spoken. Some documents are in Latin, German, or French. Or Ukrainian, which is the only one I panic about due to Cyrillic alphabet.
Last but not least, there were marriages between people of different faiths. And it's not clearly recorded. I suspect priests might have felt that if a person was being baptized, married, or buried in their church then that's enough to claim them. I've seen one note in a Roman Catholic record that says "This man comes from Ruthenian lands."
So here are some clues which may help.
The first is the given name of a child. Children are often named after a saint because of the day they were born that honored that saint or thereabouts - so you'll see a lot of girls who are baptized in a Franciscan run Roman Catholic church named Rose/Rosalia after Italian Saint Rose of Viterbo in early September. There isn't much diversity of names or honorifics of parents or family in Polish records. Children chose a Confirmation name that might honor a parent. (And use that as a middle name.)
When you get to names such as Basilius, Anastasia, Demeter and Tatiana you're probably looking at a child who has a Greek Catholic heritage, at least one parent because that name honors an Eastern saint. I've found these names in Roman Catholic records. They don't just sound Greek. They sound Russian.
Second, you'll find certain settlements had substantial populations and separate churches but others required travel. It might be easier to just go into the closest church.
Or, home births with family or midwives being the common way, a baptism could occur after birth and people might not make it into church, staying up in the mountains.
Third, you may find you do have to move over to Greek Catholic records and into records of other countries so it's worth checking into in any case if a village that figures into your heritage had a Greek Catholic Church.
Interesting to me is that Polish Roman and Greek Catholic records and Jewish records record the name of the midwife which I feel is part of a testimonial such as, "I know who the mother is. I delivered the baby." Midwives did baptized babies after birth. (Anyone can.) Notice any pattern on day born and day baptized ? The same day might mean baptized at birth.
A question of the Ruthenian ethnic identity has existed for hundreds of years, a controversial subject for sure. They are considered to be of the country from where they lived. (i.e. Russia, Poland, Hungary, Rumania....)
But if you know someone who is Ruthenian, ask them how they wish to be identified.
Here is the last but sometimes most important thing. There may be a ten to twelve day difference in the dates from the Eastern, Julian calendar that was the old calendar begun by Julius Caesar and used until 1582 throughout Europe and the Gregorian, begun by Pope Gregory used by most of Roman Catholic Europe. So basically if you're reading records of the Eastern Orthodox or Greek Catholic Church, read the dates forward and back of the date you're targeting. (Many of you are familiar with the difference in when Christmas is celebrated.
***
So, the three groups of Ruthenians are the Lemko, who are usually found in Ukraine, Poland, and Slovakia. The Hutsels, usually found in Ukraine, Romania, and Bukovina. And the Boykos, usually found in the mountains of Ukraine, Slovakia and Hungary. Ruthenians are also called Carpatho- Rusyns, Kiev Rus, Eastern Slavs, Uniates, Belarusians, and mostly Ukrainian...
They bought Saint John the Baptist cathedral.