It has large coal mines, which form the south-western portion of the extensive Upper Silesian coal fields, the largest Austrian deposit.
In 1742, however, he was induced to transfer his support to Maria Theresa, and his troops took part in the struggle against Frederick the Great during the Silesian wars, and again when the Seven Years' War began in 1756.
The only doubt arises from the existence of insect remains, referred to the order Coleoptera, in the Silesian Culm of Steinkunzendorf near Reichenbach.
The court of Vienna had treated the Silesian Protestants with tyrannical severity, in direct contravention of the treaty of Osnabruck, of which Sweden was one of the guarantors; and Charles demanded summary and complete restitution so dictatorially that the emperor prepared for war.
The Riesengebirge has of late years been made easily accessible by railway, several branches from the main lines, both on the Silesian and Bohemian side, penetrating the valleys, and thus many spots in the Riesengebirge are a good deal frequented in the summer.