I got bitten badly by the genealogy bug a few years ago, but got it mostly out of my system by writing up my findings and calling it a finished project in 2010. Once in a while I have a relapse, though. The hot thing today is genetic genealogy. You may have seen on PBS or in commercials that you can now get your DNA sequenced cheaply and enter the results into a database that will match you up with "genetic cousins."
It's not as straightforward as it sounds, because DNA base pairs change at rates that are not very accurately known. Also, if you don't sequence enough markers, you could get a false match just by random chance. So if two people match on 45 out of 50 markers, it's pretty clear they're related, but you can't really say whether they are third cousins or 10th cousins. Still, it's a good adjunct to traditional documentary genealogy. If anything, it's a reliable way to prove two people do not have a common ancestor.
I did have a great success with DNA testing, almost too good to be true. My grandfather was adopted by Mr. Henson as an infant, but the real father was known to the family. They said his name was Conley. He was supposedly a "deputy sheriff." After years of research, at the beginning of which I didn't even know which state my grandfather was born in, I discovered in the 1910 Census a Conley who was the marshal of a town near the rural area of Kentucky where Grandpa was born. Miraculously, I was able to make contact with a descendant of his on a message board, and even more miraculously, this contact turned out to be a direct male descendant of Conley who was willing to compare DNA with me. It matched!
So, genetically I am a Conley. Stories vary about whether Mr. Conley was an honorable man, but I'm stuck with his genes. This has led to some very interesting speculation. A couple years after I did the testing (my results were in a public database), some old retired guys who have time for this sort of thing emailed me out of the blue saying that my DNA was a match to a cluster of families whose names were found in an ancient Irish genealogy. The old genealogy said these names were descendants of the Three Collas, kingly conquerors of part of Ireland in the fourth century AD. A lot of genealogies, especially ones involving European royalty, are malarkey, so it was significant that many of the names really did turn out to have a common ancestor. The overlap isn't perfect - some names on the list turned out not to be related, while other people who were related had names not on the list. But it's shaping up to be a pretty solid story. The clustering is significant, and stands out distinctly from other groups that have been in the same area for centuries but whose DNA is far different.
Because it now appears that the Three Collas were real people and not just made up like King Arthur, people have become interested in where they came from. The account that seems to make the most sense to me is that they were Romano-British mercenaries brought in by one Irish king to help fight another Irish king (in those days, if you ruled over even one crummy little county, you were a king.) The legends are sketchy but they all seem to contain the element of the Collas being mercenaries. Get this:
The three sons of Eochaidh, great their fame,
The three Collas we have heard of;
Colla Meann, Colla fo Chri,
And Colla Uais the high king.
The names of the three I know,
And they slew the high king
On yon wide bright plain,
Aodh Muireadhach and Cairioll.
Cairioll, Colla Uais the king,
Muireadhach, Colla fo Chri,
Aodh, Colla Meann, great his fame;
These three were mighty beyond all strength.
- Geoffrey Keating (1569-1644), The History of Ireland, 1634, translated from Irish in 1902 by David Comyn and Patrick S. Dinneen, Vol. II, page 359. Quoted by DNA of the Three Collas.
Notice in the last stanza how each Colla brother has three names. This was the clue that led Donald Schlegel to theorize that they were Romanized Britons, because the triple name (praenomen, nomen, cognomen) is a convention found in Rome and nowhere else. The nomen, Colla, has the root col- and was found in Colchester, the oldest Roman settlement in Britain.
It's unlikely we will ever know whether there were really three Collas, because they all would have had the same genes. Their descendants would be genetically indistinguishable. Donald Schlegel suggests they were of the tribe called the Trinovantes, but not because of the legend of three brothers. The prefix tri- doesn't mean three; it's Celtic for "very". But it is true that the ancient symbol of Colchester contains three crowns.
My favorite part is that the pre-Roman ruler of the Colchester area is said to have been a King Coel, who was legendarily the grandfather of the Emperor Constantine (this cannot possibly have been true as Constantine wasn't born anywhere near Britain.) But, reputable historians assert, Old King Coel was a merry old soul, and a merry old soul was he. Furthermore, some scholars claim that he called for his pipe, he called for his bowl, and he called for his fiddlers three.