In the middle of the night following the crusaders’ first major assault on the city of Jerusalem, Clorinda burned their siege towers down. Unrecognised by Tancred, he then mortally wounded her in a fight before realising who she was, then baptised her just before she died.
The wounded Tancred feels disgust at his killing of Clorinda, and the two are carried back to his tent. Despite his injuries, he makes his farewell to her corpse. She appears to him in a dream and his emotions are reconciled following her burial.
Canto thirteen returns to the siege, and the crusaders’ need to replace their wooden towers. Ismen visits the ancient wood which is the nearest source of timber, and casts a spell to prevent any more trees from being felled there. He then reassures Aladine that he is safe, particularly as he forecasts that the weather is set to turn very hot and dry, and that Aladine should sit tight in the city rather than try to force an end to the siege as Argante wants.
Godfrey now wants to rebuild his siege towers quickly, before Jerusalem has had time to repair the damage made to its defences. He despatches men to the woods to cut down the timber which the new towers require, but they are now repelled by the bewitching of the trees. Godfrey sends troops in on three successive days, but each time they are driven out by the dire effects of Ismen’s spell.
Finally, Tancred, now recuperated from his wounds, plucks up his courage and enters the enchanted wood. He feels no ill-effects, and makes his way to its centre, where there is a cryptic inscription written on an ancient tree. The trees then speak to him, claiming to be the spirit of Clorinda and others, and warning him not to try cutting any of them down. Tancred reports this to Godfrey, who turns to other plans.
As Ismen had forecast, the weather becomes unrelentingly hot and dry. Even the nights remain hot, and crusaders are dying as a result. The nearby stream of Siloa, which had been a major supply of water, dries up, and there are deaths from dehydration. Morale collapses, with many of the crusaders questioning Godfrey’s inaction. The remaining Greeks desert and start their journey home.
Godfrey then prays for divine assistance. This brings a torrential rainstorm and the return to more comfortable conditions at last.
Canto fourteen opens with nightfall, when at last with the cooler conditions all were able to sleep properly. For Godfrey there is a vision, in which he is told to recall Rinaldo from his self-imposed exile, and to absolve him from his error. No sooner does Godfrey awake the following morning than Guelph asks him for Rinaldo’s pardon, in the hope that the knight will be brave enough to overcome Ismen’s spell, and cut wood to build their siege towers.
Godfrey agrees, leaving Guelph and a team of volunteers to find and recover the missing knight. As the group are discussing where to look, Peter the Hermit interrupts and advises them to travel to Ascalon, and there to ask the man that they meet.
When they reach Ascalon, a wizard with a white beard, beech crown, and wand tells them to follow him as their guide. He takes them into hidden caves beneath a stream, where they see the sources of the great rivers of the world, set in a huge cavern whose walls are speckled with jewels. The wizard says that this is the womb of the earth.
The wizard then tells them what happened to Rinaldo after he had freed the other knights who had been made captive by Armida, and how Rinaldo’s armour came to be made to look as if the knight had been killed.
Armida then waited at the ford on the river Orontes for Rinaldo. When he arrived, he found a column with an inscription which enticed him to go further, leaving his esquires behind him as he boarded a boat. He then came to an island which appeared quite deserted, so he decided to rest there, and put his helmet down beside him.
A little later, he heard a sound from the river, and spied a beautiful woman emerging from the water, naked. She sang a song which lulled Rinaldo to sleep, then came across intending to kill him. But when she saw him, breathing gently in his sleep, her anger melted away and she fell in love with him instead. She then put garlands of flowers around his neck, arms and feet which she had bewitched to act as bonds, had him lifted into her chariot, and abducted him.
This remarkable turn of events has been a great favourite among painters, and a particular challenge to depict in a single image. As a classical example of what Aristotle in his Poetics refers to as peripeteia, it has led to some superb narrative paintings.

In Anthony van Dyck’s Rinaldo and Armida of 1629, the key elements of the couple and attendant symbolic amorino are enriched by a second woman with non-human legs still immersed in the river and clutching a sheet of paper, and several additional amorini. Armida appears unarmed but starting to bind him with garlands, and it is possible that the letter represents her mission to murder him, which the woman in the water, perhaps a nymph, is reminding her about.
Although beautifully executed, its narrative is considerably more elaborate than Tasso’s marvellously concise description.

The most brilliant account to date is Nicolas Poussin’s justly famous Rinaldo and Armida from about 1630.

There are two quite distinctive, almost formulaic, elements within Poussin’s depiction: Armida’s facial expression, and the ‘body language’ of her posture, particularly the conflict between her arms.
Facial expressions have long been associated with different emotions, in paintings and other narrative media such as the theatre. Even late into the nineteenth century, there were collections of prints and books which showed a range of stereotypical expressions intended to help artists and illustrators who were engaged in producing narrative works. Although Poussin appears to have avoided such stereotypes, Armida’s expression is a key graphical element in understanding the narrative: she is perplexed, in a quandary, unsure whether to kill or kiss the young knight.
In the Renaissance, emphasis was also placed on the disposition of all parts of the body, and their role in conveying action and emotion. Leon Battista Alberti’s cardinal work On Painting (1435-6) devotes much of its second book, The Picture, (paragraphs 38 onwards) to instructions about the positioning of body parts in the construction of Historia, narrative painting.
Armida’s right hand represents her original intent, to murder him with her dagger, an action which the amorino is trying to stop. Her left hand, though, reaches down to touch his hand in a loving caress. Poussin manages to tell us what she had intended to do (the past), and what she is going to do next (the future): three moments in time conveyed in a single image.

Poussin’s Rinaldo and Armida (c 1635) is a later and more explicit version of this same narrative episode, in which Armida is falling in love with Rinaldo. There is a multiplicity of amorini who seem less engaged in the action. The river appears more symbolically as being poured from a pitcher. In the background, Armida’s chariot is already prepared for Rinaldo’s abduction.

Sebastiano Conca’s Rinaldo and Armida from about 1725 is a return to simpler composition, based on a central triangle, and content. Armida is drawing her sword, and looking pensive, as the sole amorino reaches from above to intervene.

Tiepolo’s Rinaldo Enchanted by Armida (1742-45) presents another permutation of the elements in Tasso’s story. Armida has already brought her enchanted flying chariot, in which there is another woman, perhaps Venus herself, with an accompanying amorino. Armida is almost undressed and unarmed, and her facial expression is more of unhappy pleading than internal conflict, while her female companion appears cold and unaffected.

Fragonard’s Rinaldo and Armida from 1760-65 is another elaborate painting with an abundance of amorini. Armida’s right hand clutches a dagger, and is restrained by two of the amorini, although it is hard to determine whether she has much facial expression.
With Guelph’s party searching for Rinaldo, Armida now whisks him away in her chariot – still fast asleep, and ignorant of what is in store for him.
References
Wikipedia on Jerusalem Delivered.
Wikipedia on Torquato Tasso.
Wikpedia on the First Crusade.
Project Gutenberg (free) English translation (Fairfax 1600).
Librivox audiobook of the Fairfax (1600) English translation (free).
Thomas Asbridge (2004) The First Crusade, A New History, Free Press, ISBN 978 0 7432 2084 2.
Anthony M Esolen, translator (2000) Torquato Tasso, Jerusalem Delivered, Gerusalemme Liberata, Johns Hopkins UP. ISBN 978 0 801 863233. A superb modern translation into English verse.
John France (1994) Victory in the East, a Military History of the First Crusade, Cambridge UP. ISBN 978 0 521 589871.
Joanthan Riley-Smith, ed (1995) The Oxford Illustrated History of the Crusades, Oxford UP. ISBN 978 0 192 854285.
Jonathan Riley-Smith (2014) The Crusades, A History, 3rd edn., Bloomsbury. ISBN 978 1 4725 1351 9.
Johathan Unglaub (2006) Poussin and the Poetics of Painting, Pictorial Narrative and the Legacy of Tasso, Cambridge UP. ISBN 978 0 521 833677.