Elliott O’Donnell – The Dead Riders (Arrow, 1964; originally Rider & Co, 1952)
Blurb
Through one of the walls of the hall, accompanied by a cold wind, came a cavalcade of grey, shadowy riders on grey shadowy horses. At their head rode a figure taller and more terrifying than any of the others. Although Blake could see but little of the face below the hood which he wore low over his forehead, he instinctively felt that the leader of that ghostly host was the Spirit of The Mighty Lovonan Wizard, Shadna Rana.
Creeping Terror 