Ólafur "Hvíti" "The White" Ingjaldsson, King of Dublin - Death date

Might be worth a bit more research.

The Wikipedia article for Amlaíb Conung actually says he died c874 (not 871/2). A footnote says an alternative date of 872 for Amlaíb's death has been proposed.

It's plausible that there really is an Irish source that says 866. It might not be reliable, but that bit shouldn't be discarded until it's been checked.

If you compare the About on Olaf's profile to his wiki page it looks to me like a straight copy and paste, but the About says 866 whereas the wiki says 871/2, i interpret this as an indication that a Geni user copied the wiki page into the About but since then the wiki page has been edited.

Charles Cawley records:-

The 10th century Pictish Chronicle Cronica de Origine Antiquorum Pictorum records that, in the second year of the reign of Constantine I King of Scotland [1065], "Amlaib cum gentibus suis" wasted "Pictaviam" which they occupied from 1 Jan to 17 Mar, but that in the third year "Amlaib" was killed by King Constantine[1155].

So we have an exact date of death for Amlaib but it depends on knowledge of Constantine I. Constantine's wiki page http://en.wikipedia.org/wiki/Causant%C3%ADn_mac_Cin%C3%A1eda actually mentions Amlaib and gives his death as "...either in 871 or 872..."

HOWEVER, it looks like Constantine took the crown of Scotland in 862 (? ie Domnall's death) which could make Amlaib's death 865.

Did Constantine's reign begin in 862 becomes the question then.

That's very typical of early medieval dates. The one you want always seems to be contingent rather than absolute, and the date that it's contingent on then turns out to be not as firm as you'd like.

Cawley doesn't tell us anything about the reliability of Cronica de Origine Antiquorum Pictorum, so that's another avenue to explore.

Could be 866 is what Wikipedia said at the time it was copied. You'd have to look at Geni's revision history and Wikipedia's revision history to know. I did take a quick look at the revision history for the Wikipedia article. The oldest version has the death date as ?874. It looks like it was 875 for awhile, then changed to 874. I didn't see a version with 866, but that doesn't mean it isn't there.

In any event, you now have a good guess for the source of the 866 date, so the About Me on Geni can be edited to show the different versions.

Hmm,
http://en.wikipedia.org/wiki/Causant%C3%ADn_mac_Cin%C3%A1eda
tells us Constantine I "...succeeded his uncle Domnall mac Ailpín as Pictish king following the latter's death on 13 April 862."

So according to Cronica de Origine Antiquorum Pictorum Amlaib is dying in 866, this seems to be the closest thing to a contemporary account?

Do you have access to the Pictish Chronical?

This is an extract quoted on Amlaib's wiki page:
"...after two years Amlaib, with his people, laid waste Pictavia; and he dwelt there from 1 January until the feast of Saint Patrick. Again in the third year Amlaib, while collecting tribute, was killed by Constantine. A short while after that battle was fought in his 14th year at Dollar between the Danes and the Scots, the Scots were annihilated at Atholl. The Norsemen spent a whole year in Pictavia.[61]"

Note the mixed references "third year" as opposed to "14th year", if "third" is actually "13th" then we could end up with 875 for Amlaib's death.

I'm getting dizzy.

I don't have access to it. You could probably find it easily in one of the online databases at a university library. I notice access is available for purchase at Brill:

http://referenceworks.brillonline.com/entries/encyclopedia-of-the-m...

It's just one of several early sources, so I would be cautious about thinking it might be more reliable than secondary sources that have looked at all of them.

Some of these other sources are also part of the Poppleton MS.
http://en.wikipedia.org/wiki/Poppleton_manuscript

A Google search comes up with quite a bit of academic discussion about the reliability of this and other sources. For example:

Controversial Issues in Scottish History
https://books.google.com/books?id=FwzspEvJC0cC&pg=PA9&lpg=P...

This gives some or all of the Cronica de Origine, beginning at p. 226. The piece you quoted in translation is in the original Latin at the bottom of p. 231.