Kaltenstein, or Cold Stone is the largest–and believed to be the most physically strong–of the Great Western Dragons, who fought Lofwyr and Nebelherr in 2012 and is suspected to be King Berthold I, the first king of the Black Forest Troll Kingdom.
Kaltenstein awakened in April or May of 2012.
In 2038 it is believed that Kaltenstein disguised himself as (or at least manipulated) a troll freedom fighter named Berthold and began to free a number of other trolls from German internment camps. He also attacked the airship Lothar Späth over Black Forest.
In 2043 the Black Forest Troll Kingdom is founded and Berthold is made its first king.
In 2061 King Berthold I mysteriously disappears. Shortly after the disappearance, Kaltenstein's lair in the Feldberg was discovered by the Troll Kingdom authorities.
There is a contradiction to the motivation or time when the fight between him, Nebelherr, and Lofwyr is said to take place in May of 2012. It has been assumed that Kaltenstein was attempting to save Feuerschwinge who had just been shot down over the SOX, however this event did not occur until September of 2012 according to Sixth World Almanac. It is possible that he was going to help Feuerschwinge attack the German Military which did start in May. But, it does not make sense on why the other dragons would not want Kaltenstein to aid Feuerschwinge's assault on the German Military, and other sources (such as Dragonfall) maintain that his attack was immediately after Feuerschwinge's fall. So either the true motivation for the fight had something else to do with dragon politics, or (most likely) the time when Feuerschwinge was shot over the SOX is wrong in one or more of the sources.
After Berthold's disappearance in 2061, Kaltenstein had still not been seen in public, leading some to believe that Kaltenstein was not Berthold.
In a discussion of Feuerschwinge on the Shadowlands BBS , Harlequin (as The Laughing Man) strongly implied that Kaltenstein was formerly mated to Feuerschwinge, which may explain his attempt to aid her, although the matter is complicated by his behavior after those events; he began systematically hunting down and destroying toxic shamans from the SOX which were suspected worshippers of the fallen Feuerschwinge.