The knitted jumper worn by little Prince Harald when his family fled Norway just ahead of the Nazi invasion in 1940 inspired many a patriotic Norwegian, and Norwegians in spirit, to knit their own. The stitch pattern is a traditional Norwegian one, possibly from Hallingdal; it is also found in traditional Faroese designs and Latvian mittens. Arne and Carlos, in the video below, call the pattern "Dovre," explaining that they do so because of a 1960s-era booklet for a cardigan using that name, which name "stuck in their heads" but that is not the traditional name for it, if there is one at all. It is sometimes called the "chess" pattern in English, for its resemblance to the game board.
Laura Ricketts published a version of Prince Harald's red-and-white jumper in the January/February 2015 issue of "PieceWork" magazine, and there is also one (in Norwegian) by Nina Granlund Sæther, both available for purchase via Ravelry.
Tasha of By Gum, By Golly came up with a more feminine version that she calls "The Princess Harald Sweater" and blogged about it here.
In this video, Norwegian knitwear designers and educators Arne & Carlos talk about the "Dovre" stitch pattern --