The movie is about a grandfather teaching his grandchildren about the
history of the Vikings, and the grandfather dies in the movie and
while the adults are discussing his burial, the grandchildren put
their grandfather in a boat send it to the middle of the lake and set
it on fire like a Viking funeral.

Hi noeta,

I believe the movie you are thinking of is "Rocket Gibraltar" with
Burt Lancaster and McCauley Caulkin.

From an Amazon review:
"This movie is a fine ensemble performance. There is the afther, Burt
Lancaster, who is reaching the end of a full life. His children and
their families are joining him for a birthday bash that will be the
talk of the town. Yet this isn't about a birthday party, it is about
connections.

Lancasters children are all enmeshed in thier own lives and families.
But it is the children who are closest to Lancaster's charecter. He
tells them stories of Vikings and valhalla and the kids take not and
remember. Lancaster expresses a final wish for what to do with his
body after he dies. He doesn't tell his children, maybe sensing their
opposition, so instead he tells the grandchildren - maybe not
expecting them to do it but convey his wish to their parents.

There is comedy, despair, anger and sadness throughout the film. It
doesn't dwell on one particular emotional level, rather it touches
them and moves on, as we all do in life."
http://www.amazon.com/exec/obidos/tg/detail/-/6304068530/ 


Search criteria:
site:.amazon.com movie vikings "his grandchildren"
 
I hope this is helpful. If you have any questions regarding my answer,
or believe this isn't the movie you remember, please don't hesitate to
request a clarification before rating. I will be glad to further
assist you.

Best regards,
Rainbow

Thank You! Thank You! I am very pleased with finding out the name of
this movie.  It was excellant and am looking forward to seeing it
again!