HENRY II, DUKE OF SILESIA
... - 1241

Henry II, aka Henry the Pious, was the son of Henry I, the prince of Lower Silesia, which is in today's Poland.

Henry II was killed by the Mongols. There's a sentence he thought nobody would ever say. The occasion? The Battle of Legnica in 1241.

And here is the map

MONGOL INVASION IN EUROPE
Click map to enlarge