It can be demonstrated that John Gower's Cronica tripertita (1400) was based on the state-official account of the tyranny of the English king Henry IV: the parliamentary “Record and Process” of the deposition of Richard II and his replacement on the throne by his cousin in 1399. Evidently, Gower was given or obtained a copy of the official account of the usurpation, and he turned it into poetry in the form of the Cronica tripertita, which then circulated as another apology for the nascent Lancastrian regime, propaganda-wise. Other evidence indicates, however, that Gower's work was not innovatory in this respect. In earlier decades of the fourteenth century, other poets were employed by other, earlier English regimes in the production of verse propaganda, basing their work too on state-supplied sources of information.
A precedent-setting episode, occurring early in Gower's career, of which he may have been aware, involved the English invasion of Castile in 1367. The events of the campaign and its culminating battle at Nájera on 3 April 1367 – when a combined Anglo-Gascon-Castilian force led by the English prince Edward (1330–76), the Black Prince, and his brother John (1340–99), duke of Lancaster, defeated the Franco-Castilian array of Enrique de Trastámara (1334–79), a bastard, and restored Enrique's half-brother Pedro (1334–69) to the kingship of Castile and León, though only briefly – are well understood from high-quality Continental sources, especially the history of Pero López de Ayala (1332–1407), the Livy translator, who was a participant in the battle, and that of Jean Froissart (c. 1337–c. 1405), who was not.