Priest writing in a church record book - how to trace it?

In my search for my relatives, I have made friends by email with a young lady in Poland. She happens to live in the town my gggf was born in. Her last name is also my families last name she is getting married in the same church my gggf was baptised in. So we are searching together. She had written to me and said that while she was at the church her and the preist looked through some of the old church books for my gggf. Not only did they find him but other siblings births and deaths. Names and all. So when she emailed me the information the was a strange word in the book. It said "his parents are francis and anna nee stasiowka. There he writes ; Jagiellonian - Jagiela."

So will someone explain to me what Jagiellonian - jagiela is. What is the significants of this name. I also have from the diocese a letter with the births of the american born children and to my surprise one is named Ladislaw who our family called William. When I looked up the name Ladislaw to see what it was in english I found this sentence witht he explaination of the name ( It appeared in the dynastic clans of the Piasts & Jagiellonians, as well as in the ruling clans of Bohemia & Hungary & has long been popular in poland.

So If a preist writes int in a church record book and I find it with the name in another article then it must mean something. Do I try to trace it or what? I am stuck again but I honestly never thought I would get this far. I hope someone can explain to me what the heck this means for my family.

Would someone happen to have a list of Jagiellonians? I posted before a name on gggf baptismal certificate that we can not make out and her maiden name looks like jagiela>>. We still have not figured out the first name.

Thanks

Wladislaus dei gracia Rex Polonie, nec non terrarum Cracovie, Sandomirie, Siradie, Lancicie, Cuyauie, Lituanie princeps supremus, Pomeranie, Russieque dominus et heres, etc.

Your post is a bit unclear. The list of Jagiellonian kings in Poland is readily available in Wikipedia or elswhere. This surname in Polish is "Jagiełło" and apart from being the name of the first Polish-Lithuanian king (Władysław Jagiełło), it is an ordinary family name in Poland these days, by no means asocciated with the royal name of the Jagiellonian dynasty or a noble name of any kind.

Władysław (Ladislas) is a common Christian name in Poland, not at all popular among the younger generarations these days, but it used to be a very popular Polish Christian name in the past. The kings who also bore this name were: Władysław Herman, Władysław £okietek (of the Piast dynasty), Władysław Warneńczyk (od the Jagiellonian dynasty, son of Władysław Jagiełło), Władysław IV (of the Vasa dynasty)