Apparently, up there between Estonia and Russia, ice in early April can be pretty thick – so much so that on April 5, 1242 the Republic of Novgorod and the Teutonic Knights could fight a battle on the frozen lake Peipus.

But not quite thick enough…  according to one version of the story, Novgorodian Prince Alexander Nevskij ordered his men to hit the ice with their lances, which weakened the surface enough to break, and swallow the already battered Teutonic Knights.

Actually, it is more likely that the Knights retreated to the wrong side of the lake, where the ice was already thinning – and the heavy armours and cold water did the rest.

The sources do not agree about the dimensions of the battle and the number of casualties, and historians still argue about its impact: a huge affair of vast consequence, or little more than a skirmish?

Either way, it was one of those striking events who seem made to grow roots in popular imagination, and thrive there through the centuries.

It certainly helps that Eisenstein depicted it in this way, with Prokofe’ev’s music to boot: