1. Not a true etymology. The name is first recorded as Hróiskelda, in a poem of c. 1050 (MS. 13th century), thus Hroir's Spring, rather than Hroar's/Ro's. For a fuller version of these events and the subsequent career of Rolf, see Saxo, Book II.
2. Láland, according to the Annals of Lund, and other sources, a Danish island.
3. The Swedish king is Athisl in the Annals of Lund, corresponding to Icelandic Aðils, Old English Eadgils. For other dog-king tales, see The Saga of Hakon the Good (Hákons saga ins góða) 13, and Saxo, Book VII.
4. The island of Læsø lies off the north-east coast of Jutland. Old Danish Læ (Ler in Saxo, where he is one of Helghe's generals) = Icelandic Hlér, also called Ægir, the giant king of the sea. See Skáldskaparmál 1 and 23. In Hversu Noregr byggðist (How Norway was Settled) 1, Hler is the son of Fornjot; his three brothers each rule over a different element, Hler's being the sea. His name forms the basis for many marine kennings.
5. Snio's reign is in Saxo, Book VIII. Here he is the son of Siward, and succeeded in turn by his son Biorn. While Saxo doesn't echo the Chronicle's disapproval, he does describe a time of want in Denmark. Snio tries to counteract the grain shortage by banning beer, on pain of death, but is eventually persuaded to reverse this law, in the face of popular resistance.
6. According to the Annals of Lund: "He saw three beavers collecting wood, one of whom, who was called the servant, or "beaver-thrall", collapsed on the ground with his legs stuck out. The other beavers placed the wood between his legs and walked in front, dragging him along like oxen."
7. In the Annals of Lund, he is to ask the giant by what death King Snio will die. Snio hopes that Roth (Røth 'red') will be killed. Lee refuses to answer unless Roth tells him three true things (this triad motif is common in Saxo).
8. Properly Hiarwarth, as in the Annals of Lund.
9. Latinised form of Skuld.
10. Both = Bous in Saxo = ODan. bóe, OIc. búi. The name was sometimes Latinised as Boethius, hence Both.
11. Rørik Slængeborræ, a corruption of Slænganbøghe (= Old Icelandic Hrærekr slöngvanbaugi) 'ring-slinger', in other words "very generous with giving rings", see Saxo, Book III. Since rake 'the proud' can also mean 'dog', this may have occasioned the dog-king legends.
12. Ambløthæ = Shakespere's Hamlet, see Saxo, Books III & IV, where he is named Amleth, and his mother Gerutha. Saxo's Amleth is killed fighting Wiglec.
13. Presumably a message carved in wood, as in Saxo, who adds that this was "a kind of writing material frequent in old times." Many and diversely-intended runic messages have been discovered on strips of bark, from Bergen for example, although the widespread use of runes in personal communication is attested rather for the medieval period, 12th to 14th centuries, than earlier.
14. Wihtlæg in Old English royal genealogies, son of Woden, and father of Wermund. In Saxo: Viglet, who kills Hamlet and takes his wife.
15. See Saxo, Book IV. The story is also told by Saxo's contemporary Sven Aageson, and briefly in the Annales Ryenses. (He is called Uffo in these Latin versions – Danicized back to Uffe in Elton's translation). Offa's duel is alluded to in the Old English poem Widsith (35-44); here in this early source Offa is not Danish but an Angle, and his foes Myrgings or Sweaves, rather than Germans/Saxons. But by the time of the Danish accounts, the tale had undergone modifications of its own in England. In the Vitae Duorum Offarum (Lives of the Two Offas), the scene is set in England, though many of the details (Offa's dumbness, and his fighting two against one) are preserved.
16. In Saxo, Uffo explains his decision to fight two opponents, saying that this will remove the shame of an earlier incident in which a certain King Athisl of Sweden was killed by two Danes, Keto and Wigo, who thereby broke the terms of the duel. It had become a "standing reproach to the Danes." The slaying of Athisl is also mentioned in Annales Ryenses, and by Sven Aageson, who adds that this shame was the cause of Uffe's youthful inability to speak. Regarding the identity of Athisl, see Chambers: "Widsith: A Study in Old English Heroic Legend", pp. 92-94. Chambers doubts this Athisl was originally king of Sweden, since the only known Swedish king of this name is the Adils of Hrolf's Saga, who died by falling from his horse at the sacrifice of the goddess (Heimskringla I, 29), or according to Saxo, through too much drink, while celebrating the death of Hrolf. Instead, Chambers, and others, have identified the Athisl of Offa's tale with Eadgils of the Myrgings (Widsith 93-96).