[quote="Adam_Cook, post:18, topic:441447"]
Father, correct me if I am wrong, but the law also says that should a person come back to the Catholic Church, he is to join the Sui Juris church of his Father's lineage, or from the defected time.
Yes, that's right.
Now my family has been in the US South for well over 300 years, we have a direct line that says that we were protestant the whole time. Furthermore, majority of our research in family lineage has lead us back to the Middle East, in which case we would have been Orthodox or maybe even Eastern Catholic. Based off this information, and the Code of Canon Law, the defection would have taken place from a non-Roman Church, yet I was baptized, confirmed and received first communion in the Roman Church in 2011. While the sacraments themselves cannot be voided, or considered null because both the Orthodox and Catholic churches are considered to have valid sacraments, does this mean that ritually speaking since my defect took place, on the Father's side, from an Eastern rite (no matter the case that it was over 300 years ago) that I should technically have been in the Byzantine Rite Sui Juris, not the Roman rite?
This is going off the basic premise that we follow the Code of Canon Law, as the Roman Ordinaries do every time I try to bring members into my Byzantine rite, declaring they defected from a Roman rite ancestor and therefore are of the Roman rite. Just a question, curious for the answer.
One thing I don't understand about the question: Did the ancestor (paternal line) leave the Latin Church or one of the Eastern Churches? You say both things, so I don't know which actually applies. Or are you saying that the Latin clergy are the ones saying that the ancestor left the Latin Church, but you disagree?
In any case, if you can actually go back 300 years and document that this ancestor was indeed an Eastern Catholic or Orthodox (and sometimes, that's just a matter of geography ,country or village, or sometimes family name, but not always) you would be right to claim canonical status in the corresponding Catholic Church sui iuris.
Some things to note:
*]If those family members are not-yet-Catholic, you don't need to prove anything to the Latin ordinaries. You only need to prove that to the Eastern Catholic pastor. He then knows that he's in the right by baptizing or receiving them, and he can note in the register that they are canonically members of that Church.
*]If those family members are Catholic now, and this is a question of making notes in baptismal registers that the members are Eastern rather than Latin, then that might involve the Latin ordinaries. If you are encountering obstacles there, my suggestion is to communicate with the Eastern Eparchy's canonical vicar. He certainly knows the law and an explanation from him on his official letterhead will carry considerably more credibility than "I read it on the internet." The point is that he can help you resolve this.
]Caution: You say that you know your ancestor was from the Middle East. If you're going to invoke canon law here, you need to have your all your facts. It's one thing to say "likely Eastern Catholic or Orthodox" even if that's extremely likely. But if you try to invoke the canons, that's not enough. You would have to go deeper than that and be certain of the specific Church sui iuris. For example, if the ancestor was Melkite, then you have no claim to membership in the Ruthenian Church. If he was Maronite, you have no claim to membership in the Mekite Church. Etc. etc. The point is that you might need to do a little more research---I don't know.
One cannot claim simply "Eastern Catholic" membership. One can only claim membership in a specific Church *sui iuris.
*]If this is a matter of family members who were baptised and raised as Latin Catholics, but who now want to become Byzantine it might prove easier to do a formal transfer rather than invoke the canons (unnecessary, yes, but still easier). HH Francis has made transferring Churches rather easy. Again, I'll say that if you encounter obstacles, contact the judicial vicar for the Byzantine eparchy.