Don’t forget Vlad Dracul:
http://www.eskimo.com/~mwirkk/castle/vlad/vladhist.html
http://www.draculas.info/vlad_iii_dracula/
From one of the articles:
“Death by impalement was slow and painful. Victims sometimes endured for hours or days. Dracula often had the stakes arranged in various geometric patterns. The most common pattern was a ring of concentric circles in the outskirts of a city that was his target. The height of the spear indicated the rank of the victim. The decaying corpses were often left up for months. It was once reported that an invading Turkish army turned back in fright when it encountered thousands of rotting corpses impaled on the banks of the Danube. In 1461 Mohammed II, the conqueror of Constantinople, a man not noted for his squeamishness, returned to Constantinople after being sickened by the sight of twenty thousand impaled corpses outside of Dracula’s capital of Tirgoviste.”