This work is a continuation of the "Orlando Innamorato" of Matteo Maria Boiardo, which was left unfinished upon the author's death in 1494. It begins more or less at the point where Boiardo left it.
This is a brief synopsis of Boiardo's work, omitting most of the numerous digressions and incidental episodes associated with these events:
To the court of King Charlemagne comes Angelica (daughter to the king of Cathay, or India) and her brother Argalia. Angelica is the most beautiful woman any of the Peers have ever seen, and all want her. However, in order to take her as wife they must first defeat Argalia in combat. The two most stricken by her are Orlando and Ranaldo ("Rinaldo" in Rose).
When Argalia falls to the heathen knight Ferrau, Angelica flees -- with Orlando and Ranaldo in hot pursuit. Along the way, both Angelica and Ranaldo drink magic waters -- Angelica is filled with a burning love for Ranaldo, but Ranaldo is now indifferent.
Eventually, Orlando and Ranaldo arrive at Angelica's castle.
Others also gather at Angelica's castle, including Agricane, King of Tartary; Sacripant, King of Circassia; Agramante, King of Africa and Marfisa ("Marphisa" in Rose), an Asian warrior-Queen.
Except for Orlando and Ranaldo, all are heathen.
Meanwhile, France is threatened by heathen invaders. Led by King Gradasso of Sericana (whose principal reason for going to war is to obtain Orlando's sword, Durindana) and King Rodomonte of Sarzia, a Holy War between Pagans and Christians ensues.
Ranaldo leaves Angelica's castle, and Angelica and a very love-sick (but very chaste and proper) Orlando, set out for France in search of him. Again the same waters as before are drunk from, but this time in reverse -- Ranaldo now burns for Angelica, but Angelica is now indifferent. Ranaldo and Orlando now begin to fight over her, but King Charlemagne (fearing the consequences if his two best knights kill each other in combat) intervenes and promises Angelica to whichever of the two fights the best against the heathen; he leaves her in the care of Duke Namus. Orlando and Ranaldo arrive in Paris just in time to repulse an attack by Agramante.
Namus' camp is overrun by the heathen. Angelica escapes, with Ranaldo in pursuit. Also in pursuit is Ferrau, who (because he had defeated Argalia) considers Angelica his. It is at this point that the poem breaks off.
While the Orlando-Ranaldo-Angelica triangle is going on, the stories of other knights and their loves are mixed in. Most important of these is that of the female knight Bradamante (sister of Ranaldo), who falls in love with a very noble heathen knight named Ruggiero ("Rogero" in Rose). Ruggiero, who is said to be a descendent of Alexander the Great and Hector, also falls in love with Bradamante, but because they are fighting on opposite sides it is felt that their love is hopeless.
Nevertheless, it is prophecised that they shall wed and found the famous Este line, who shall rise to become one of the major families of Medieval and Renaissance Italy (it is worth noting that the Estes where the patrons of both Boiardo and Ariosto).
Opposed to this prophecy is Atlantes, an African wizard who seeks to derail fate and keep Ruggiero from becoming a Christian. By the end of the poem, Ruggiero is imprisoned in Atlantes' castle.
However, Bradamante (who has decided to follow her heart) is in pursuit of her love, and is not too far away. It is the Bradamante-Ruggiero story that eventually takes center stage in Ariosto's work.
Other characters of importance: Astolfo, a Peer and friend of Orlando, who is kidnaped by the evil witch Morgana and her sister Alcina; Mandricardo, a fierce but hot-headed heathen; and a young knight named Brandimarte, who falls in love with (and wins the heart of) the beautiful Fiordelisa ("Flordelice" in Rose). All play major or semi-major roles in the events of Ariosto's poem.
