The O'Cahan Clan of Ulster, and Wikipedia
As I was trying to explain to a cousin how our Buchanan family could come from Ireland rather than Scotland, it occurred to me that Wikipedia would have a good article on the Plantation of Ulster. I found one and sent her the link. http://en.wikipedia.org/wiki/Plantation_of_Ulster
While reading Wikipedia articles on Irish history, I found the one on the O'Cahans. It doesn't mention Anselan who was the founder of the (Scottish) Buchanan clan, but has some interesting information on the destruction of the Irish clan his father had ruled 600 years previously. http://en.wikipedia.org/wiki/O%27Cahan
I was surprised to see that it refers to one of my favorite Irish melodies.
'Rory Dall O'Cahan, an Irish harpist of the 17th century, may have penned the popular Irish tune "The Derry Air" or, "Londonderry Air", in order to lament the destruction of the O' Cathain Clan. Consequently, it may have been originally called "O'Cahan's Lament". The tune is best known as the accompaniment to the song "Danny Boy".'
I was unaware of a tenuous family connection to this beautiful and haunting old melody. I found it somewhat touching.
Anselan is mentioned in a separate Wikipedia article (Note the various spellings of the name.) http://en.wikipedia.org/wiki/Anselan_O_Kyan
So when you are trying to explain something complicated, Wikipedia
may be able to save you a lot of work. Studies have shown it to be as accurate as major "print" encyclopedias and it is frequently more comprehensive than they are.