Little is known about the Norwegian Þorbjǫrn hornklofi ‘Horn-cleaver (?)’. Skáldatal (SnE 1848-87, III, 253, 261, 273) names him as a poet of Haraldr hárfagri ‘Fair-hair’ (r. c. 860-c. 932). Judging from Fsk (ÍF 29, 59), he seems to have spent his whole life at the court of this king. Þorbjǫrn is the composer of two poems about Haraldr, Glymdrápa (Þhorn Gldr) and Haraldskvæði (Þhorn Harkv). Skálda saga, an anecdote about skalds preserved in Hb, and hardly likely to be historical, depicts him as one of three skalds, the other two being Auðunn illskælda ‘Bad-poet’ and Ǫlvir hnúfa ‘Snub-nose (?)’, each of whom attempts a romantic encounter with the same rich widow and then bemoans his failure in a lausavísa (see Auðunn Lv 2, Þhorn Lv, Ǫlv Lv 2). The three skalds are also named in Egils saga (ÍF 2, 19) as Haraldr’s favourites. They occupy places of honour in his hall, with Þorbjǫrn between the other two.
In the prose sources Þorbjǫrn is predominantly referred to only by his nickname Hornklofi. To date there is no satisfying explanation of this word. It is attested in the Þulur as a raven-heiti (see Þul Hrafns 1/5III and Note), but it does not occur in that sense in the surviving body of skaldic poetry. Scholars have claimed that the nickname refers to Þorbjǫrn’s device, in Þhorn Harkv, of having a raven speak in his stead (SnE 1848-87, III, 408; ÍF 26, 101 n. 1). Fidjestøl (1991, 126) is, however, justified in doubting this interpretation. An alternative possibility would be to link the nickname to Egill Hfl 16/6-7V (Eg 49): en jǫfurr heldr lǫndum hornklofi ‘and the ruler holds his lands by a hornklof’. But hornklofi here must be the dative of neuter hornklof, whereas Þorbjǫrn’s nickname is a masculine n-stem, and unfortunately the meaning of this passage is obscure, though hornklof seems to be some kind of tool.