 The basic framework is from the "Chronicle of Ireland", but to this has been added a variety of material whose source is unknown, perhaps including early sagas, which concerns Cerball.The "Fragmentary Annals" were intended to magnify Cerball's achievements, and to present his dealings with Vikings and Norse–Gaels in a favourable light.If the various annals are partisan, the remaining sources which concern Cerball are notably unreliable.