Born in 1558, Thomas Kyd began life with a series of good omens. He was the son of a prosperous middle-class family; his father, Francis Kyd, was a scrivener—a type of scribe that was very important in the complex world of Elizabethan law. When he was seven, Thomas began to attend the Merchant Taylors school, a new and modern school for boys. Admission to Merchant Taylors required a significant knowledge of either Latin or Greek as well as the Bible, so Thomas's entrance was no small accomplishment. In fact, among his classmates at the prestigious academy was Edmund Spenser, future author of the Elizabethan epic poem The Faerie Queene. There was little hint, in Kyd's early events, of the misfortunes and sufferings that would plague his final years, sufferings almost worthy of one of his tragic protagonists.

It was at school that Kyd probably first encountered the works of classical authors, such as Virgil and Seneca, who later on would have such a profound impact on him. After completing his education at Merchant Taylors, Thomas did not attend either of Cambridge or Oxford, as did his fellow playwright and sometime friend Christopher Marlowe. Instead, he probably became apprenticed in his father's trade. He also found employment as a translator, but it is believed that by 1583 (or thereabouts) he was already writing for the stage. Here he was to make his reputation and gain lasting fame mainly as the author of The Spanish Tragedy—one of the most popular, beloved, parodied, reviled and influential plays of the entire era, a play that was still being performed and read fifty years later and was to shape the work of all future tragedians to come, including Shakespeare.

Tragedy had first achieved greatness in ancient Greece, in Attica (the region surrounding Athens), where it developed out of religious festivals that celebrated the cult of the god Dionysus. The stories of Greek tragedies generally focused on a somehow gifted protagonist, who, through some act of hubris, suffered incredible misfortune, which usually culminated in a kind of redemptive moment of understanding and usually death. This brief flowering of tragedy was followed by an extremely long hiatus during which tragedy was virtually absent from the drama of the Western world, with the exception of some crude Roman attempts to imitate the Greek masters. And tragedy was almost entirely absent from the Christian drama, which generally tended to focus on celebrating the morality of Christ or, especially in the fifteenth and early sixteenth centuries, inculcating morals through the use of morality plays. It was only with the Elizabethans, most critics agree, that tragedy regained its viability and its existence as a living art form. This would make The Spanish Tragedy a very important play, since it may be the first extant "Elizabethan classic" of the tragic genre, though this depends on whether it was written before or after Marlowe's Tamburlaine I & II and Doctor Faustus.

Read about some classics of ancient Greek tragedy, Sophocles’s Oedipus plays.

Interestingly enough, Kyd took as his model not the ancient Greeks, but the Roman playwright Seneca, whose blood-soaked tales of the downfalls of royal families proved fascinating to the Elizabethan mind. Kyd took Senecan conventions, however, and used them to create a type of play, known as the revenge tragedy, that would serve as a fertile genre for contemporary playwrights. Shakespeare's Hamlet became the most celebrated example of the revenge tragedy (as well as being perhaps the most celebrated play ever written). Kyd, interestingly enough, is rumored to be the first playwright ever to put the story of Hamlet, Prince of Denmark onto the stage, but his version was much less popular than Shakespeare's and has been lost to history.

But Kyd's play does not need to be justified in terms of its effects on later dramatists, since it was a huge success in its own right and was extremely popular with contemporary audiences despite (or perhaps thanks to) its gory violence and sometimes over-the-top rhetoric. This is surely due to Kyd's talent and craft as a dramatist and writer, but it may also have to do with the topical relevance of Kyd's themes.

The theme of revenge, for example, was a very controversial one in Elizabethan times. It is difficult to gauge the exact state of the Elizabethan mind with regards to revenge, because much of what survives on the subject comes from the preachers who were trying to discourage it. But we have reason to believe that there was a conflict between the old custom of seeking private revenge for wrongs done to one's family, inherited largely from the Anglo-Saxon and Danish influences on English culture, as well as from the Christian injunction of Vindicta mihi; "Vengeance is mine, sayeth the lord; I will repay". In other words, for the Christian, revenge against wrongdoers is the responsibility of God, not men. In Elizabethan times, a third factor had entered into the debate, namely the increasingly centralized and powerful state, which also discouraged private revenge in favor of revenge under the auspices of the law. In such circumstances, there was probably a great deal of confusion as to the moral status of revenge, though some types of revenge were definitely held to be worse than others: for example, a hot-blooded revenge committed in a fit of passion was preferable to a cold-blooded revenge, carefully, methodically plotted out in a Machiavellian manner. Though they abhorred Machiavellianism in public, the Elizabethans were fascinated when it was represented on stage, and most of the interesting avengers of Elizabethan drama, including Hieronimo, the hero of The Spanish Tragedy, employ deception and ruse to achieve their ends.

Another emotion that Kyd may have evoked was the strong anti-Spanish sentiment prevalent among his countrymen. Kyd wrote his play sometime between 1582 and 1592, most likely in the late 1580's. 1588 was the date when the first Spanish Armada—the fleet built by Philip II of Spain to invade England—was defeated, and Spain was regarded during that time as England's most hated enemy. The conflict had religious significance in the public mind, with the Spanish begin regarded as the anti-Christ and the English representing God's chosen people. An Elizabethan audience may have therefore been somewhat pleased at the denouement of the tragedy, where the royal lines of both Spain and Portugal are wiped out in a frenzied orgy of violence.

It is ironic that Kyd's play—and therefore his success and fame—may have been party due to this English xenophobia, for it was on suspicion of writing threatening anti-foreigner graffiti that Kyd's lodgings were searched by agents of the Queen in 1593. They found no anti-foreigner treatises, but they did find a pamphlet which they deemed "atheistical." Thus Kyd ended up in prison, being tortured on suspicion of spreading heresy and atheism. Kyd protested that the pamphlet belonged to Marlowe, with whom he had been roommates in the summer of 1591, and that it had accidentally been shuffled in among his papers; Marlowe was killed in a tavern brawl before he could confirm Kyd's testimony.

By the time Kyd was released, he had probably been extensively tortured. Moreover, his reputation had been ruined, and the lord on whom he had previously relied on for patronage now turned a deaf ear, unconvinced of Kyd's innocence. Kyd spent the last year-and-a-half of his life in abject poverty, completing a translation of Robert Gardiner's play Cornelia from the original French, in the hope of establishing a patron in the Lady to whom the translation was dedicated. She did not fulfill his hope. He was dead by the end of 1594, as is known from a court document in which his mother, shortly after his death, in effect disowned him, to avoid having to pay his debts. He thus died alone and penniless, but not before having unknowingly bequeathed to the Elizabethan age what may be its first masterpiece and a genre that was to produce that age's greatest accomplishment.