ORAC
I think I'm getting bogged down enough in semantics in another place (too much time on my hands!).
However, I wouldn't rely too much on amateur sites on tripod.com for my history.
Cinaed (Pictish) mac Alpin's (Dalriadan Scots) own name underlines his own mixed ancestry. Actually the Dalriadan Scots and Pictish societies were well integrated by the 9th Century (they were both Celtic peoples, one P and one Q). Kings of both peoples shared mixed ancestry for at least the preceding 100 years.
The alleged 'treason' of MacAlpin can be as easily interpreted as merely an internecine dynastic struggle.
How the Scots could be said to have wiped-out the Pictish Church is beyond me since the Picts were evangelized (and their church was set up by) the Scots St. Columba and his successors; As, indeed, were the 'heathens' in Northumbria.
Since one of the more vigorous Pictish tribes (the Goddodin) had bogged-off to North Wales, and the Church was staffed by Gaelic speaking priests, I suppose it's no wonder the Pictish language died out in Scotland.
Calling that a conquest is, I think, rather over-stepping the mark. Our Pictish brethren are still among us!