The first fortifications in the region were as old as around the 500 a.a.H, during the Human-Kanov wars, as it was a contested region between humans and Kanovs.
The stone keep would be build around of the 1700 a.a.H by the Konolardos -one of the porfírios kanov nations- as the tensions between the Kanov and the demons were on the rise: tensions that would end in the Kanovhook wars.
The castro was to protect the western borders of the eastern lands of the Konolardos from the forces of the black dragons of Brûm and the dark legions of the demons, along with other similar fortifications, keeps and watchtowers the Konolardos built during the Kanovhook wars.
With the Campaing of Western Konolardia and the advance of the forces of the lycantrophe demon lord Finsternis at the 1773, the castro was able to hold the first invasion of the demonic dark legion, givig refuge to the kanov families of the rgeion, but will fall at the 1780 a.a.H, with the second invasion of the Lycantrope king. The castro was sacked and burned, along with all the Kanovs -with their families and possetions- being slayed, aside some lucky sirvivors who told the tale of the howling and yelling of the victims, who where slaughtered by the werewolves in the stone keep. After the fall of the castro, the wooden fortifications and structures where burned, leaving the werewolves the stone keep as a ruin.
Since then, the keep was deemed as cursed by the Kanovs, and for the rest of the Kanovhook wars will only see some scarce use by bandits or werewolf packs as a refugee for short time.
After the Kanovhook wars, the ruin was part of the White Fang werewolf clan territory in the newly created Mondwargh. Neither them gave the ruins an use, aside as a sporadic camp, until the last years of the First War of the Power, when was used to garrison forces, as the Dark Legion massed their last armies against the Whide Axis, but no recorded battle was fought in the area, but it was briefly used by the marching human-elven army.
After that, between the 2223 a.a.H to the 2400 once again the ruins would remain abandoned, until the reign of Hel the Oathbreaker as alpha of the White Fang, who as she grew more paranoid of her own subjects, decided to use the ruins of the fort as her refugee, refurbishing it for her own use. It's supposed this is from when come the name of the Howling Keep, but some say it may preceed it instead from the times of the Kanovhook wars.
During the reign of Pumori White Fang, there will be a process of expansion and fortification of the decaying ruins. Around the Castro, a settlement was founded, which soon developped into the city of Howls.