I was looking at a record for Edward Bergin and his wife Mary Malone. They are my great great grandparents, born in County Laois, Ireland. There they had five children, 3 boys and 2 girls. The thing that I focused on was Edward's parents: Timothy Bergin and Margaret Kavanagh. So I decided to search Timothy Bergin on ancestry.com and I used a birth year of about 1820. Well, lo and behold, I found a baptismal record for Dan Bergin, dated 9 Jan 1846. The record lists his parents as Tim Bergin and Margaret Kavanagh, it also lists sponsors (Godparents) as Pierce Dowling and Mary Costello. It appears that the place is Clonlahy (I think).
This record is 173 years old, handwritten in a ledger book and you can read it like it was written yesterday. The place of baptism is listed as Borris-in-Ossory, Laois, Ireland and the Diocese is Ossory. This is the same place that I found the record for the baptism of Edward, as well as, his marriage to Margaret Kavanagh. I also found baptismal records for all five of their children in the same place. So, I am confident that Dan is the younger brother of Edward (my 2X great grandfather). If I'm wrong, I can always blame it on lingering effects of anesthesia, so this is a win-win.