Lord palmerston famously said that only three people understood the Schleswig-Holstein question. But BBC4 is giving British viewers the chance to add to that number by screening 1864 (16 May), an ambitious historical drama from Danmarks Radio, the makers of The Killing and Borgen. These first two episodes of eight started with a voice-over remembering the 1850s, when “Denmark was a country under the sun, and no one could have imagined that the most bloody defeat was about to happen.” Having just enjoyed a successful military campaign to keep the Prussians out of Schleswig, the Danes were inculcating their children in the virtues of Danishness. “God loves us the most,” said their teacher. Then the soldiers came home, led by Didrich (Pilou Asbaek, Borgen’s Kasp