The work belongs to the Italian Renaissance tradition of the romantic epic poem, and Tasso frequently borrows plot elements and character types directly from Ariosto's Orlando furioso. Tasso's poem also has elements inspired by the classical epics of Homer and Virgil (especially in those sections of their works that tell of sieges and warfare). One of the most characteristic literary devices in Tasso's poem is the emotional conundrum endured by characters torn between their heart and their duty; the depiction of love at odds with martial valour or honor is a central source of lyrical passion in the poem.
Tasso's choice of subject matter, an actual historic conflict between Christians and Muslims (albeit with fantastical elements added), had a historical grounding and created compositional implications (the narrative subject matter had a fixed endpoint and could not be endlessly spun out in multiple volumes) that are lacking in other Renaissance epics. Like other works of the period that portray conflicts between Christians and Muslims, this subject matter had a topical resonance to readers of the period when the Ottoman Empire was advancing through Eastern Europe.
The poem was hugely successful, and sections or moments from the story were used in works in other media all over Europe, especially in the period before the French Revolution and the Romantic movement, which provided alternative stories combining love, violence, and an exotic setting.
Tasso began work on the poem in the mid-1560s. Originally, it bore the title Il Goffredo. It was completed in April, 1575 and that summer the poet read his work to Duke Alfonso of Ferrara and Lucrezia, Duchess of Urbino. A pirate edition of 14 cantos from the poem appeared in Venice in 1580. The first complete editions of Gerusalemme liberata were published in Parma and Ferrara in 1581.
The poem, which in detail bears almost no resemblance to the actual history or cultural setting of the Crusades, tells of the initial disunity and setbacks of the Christians and their ultimate success in taking Jerusalem in 1099. The main historical leaders of the First Crusade feature, but much of the poem is concerned with romantic sub-plots involving entirely fictional characters, except for Tancredi, who is identified with the historical Tancred, Prince of Galilee. The three main female characters begin as Muslims, have romantic entanglements with Christian knights, and are eventually converted to Christianity. They are all women of action: two of them fight in battles, and the third is a sorceress. There are many magical elements, and the Saracen side often act as though they were classical pagans. The most famous episodes, and those most often dramatised and painted, include the following: