The story describes how a group of sorcerers work to destroy the Hodeirah family in an attempt to prevent a prophecy of their future doom from coming true.
With the ring, Thalaba travels across the Middle East to find a way to defeat the evil sorcerers.
In the end, Thalaba is able to stay true to Allah and is guided by the prophet Mohammad in destroying the sorcerers.
However, other critics felt that the lack of a strong lyrical structure and the use of Middle Eastern myths detracted from the poem.
The basis for Southey wishing to write long poems came from his private reading of literature while attending Westminster School as a boy.
Although finished, Southey continued to work on fixing the end of the poem until January 1801 after receiving suggestions from his friends.
After Portugal went to war with France and Spain, Southey left the country and he returned to England in June 1801.
Time passes and Thalaba settles into a pastoral life at Irem and plans to marry Moath's daughter, Oneiza.
[5] Thalaba travels past Baghdad onto the ruins of Babylon to find Haruth and Maruth, two angels that know about magic.
The two continue to travel into the dwelling of Haruth and Maruth and, when Mohareb finds out that Thalaba is not evil, attacks him.
[6] Thalaba travels to the land of Aloadin, who owns a great garden paradise, and he is invited to feast with the people, but he is unwilling to imbibe alcohol or be taken in by the dancing women that seek to entice him.
While mourning, a spirit that appears to be Oneiza begins to haunt Thalaba and claim that God disapproves of the young warrior.
After wandering through snow, Thalaba comes across the Font of Fire with the sleeping Laila trapped inside.
However, Thalaba refuses to commit vengeance and he travels onwards until he arrives at a small boat waiting for him.
Southey's purpose in Thalaba, however, is to describe as many of the various myths and superstitions that he can, and this interferes with the resolving of moral problems within the story.
Various instances of the sorcerers and sorceresses are added to the story to emphasise the evil of magic along with tempting Thalaba with power.
[12] Other images, such as Thalaba reclaiming his father's magic sword, are symbols that effectively reinforce Southey's moral themes.
To the contrary, the heavily represented magic ring is used to protect Thalaba with little explanation as to how it works and there is no moral statements tied to its use.
[13] Ernest Bernhard-Kabisch pointed out that "Few readers have been as enthusiastic about it as Cardinal Newman who considered it the most 'morally sublime' of English poems.
"[14] An anonymous review in the September 1801 British Critic claimed, "A more complete monument of vile and depraved taste no man ever raised [...] He has, therefore, given a rhapsody of Twelve Books in a sort of irregular lyric, so unlike verse or sense, that if it were worth while to present our readers with a tissue of so coarse a texture, we could fill whole pages with specimens of its absurdity.
His work will not incur the censure passed by the late Mr. Collins upon his Persian Eclogues, namely, that, from erroneous manners, they were 'Irish.
Among the sins of our youth, we, like him, have traded in desultory versification, but have long been brought back to lyrical rhyme, and heroic blank verse.
"[17] An anonymous review in the January 1802 Monthly Magazine stated, "The fable or story of Thalaba is perhaps too marvellous: every incident is a miracle; every utensil, an amulet; every speech, a spell; every personage, a god; or rather a talismanic statue; of which destiny and magic overrule the movements, not human hopes and fears—not human desires and passions, which always must excite the vivid sympathy of men.
[18] The review continued, "Whatever loss of interest this poem may sustain, as a whole, by an apparent driftlessness of the events and characters, is compensated by the busy variety, the picturesque imagery, and striking originality of the parts.
In the October 1802 edition, he claimed that Southey "belongs to a sect of poets, that has established itself in this country within these ten or twelve years, and is looked upon, we believe, as one of its chief champions and apostles ... As Mr Southey is the first author, of this persuasion, that has yet been brought before us for judgment, we cannot discharge our inquisitorial office conscientiously, without premising a few words upon the nature and tendency of the tenets he has helped to promulgate.
"[20] He continued to discuss the flaws of the British Romantic poets before returning to Thalaba when he argued, "The subject of this poem is almost as ill chosen as the diction; and the conduct of the fable as disorderly as the versification ... From this little sketch of the story, our readers will easily perceive, that it consists altogether of the most wild and extravagant fictions, and openly sets nature and probability at defiance.
Each is strikingly descriptive ... but the personages, like the figures of landscape-painters, are often almost lost in the scene: they appear as the episodical or accessory objects.
This stunning impression of the style gives pain, we believe, especially to mere English scholars, and to those whose comparison of art is narrow and confined, but falls within the limits of pleasure, and is even a cause of luxurious stimulation, to readers of a wider range and a more tolerant taste.