"Cronica Walliae" is the earliest and largest extant work of antiquary and map-maker, Humphrey Llwyd. Completed in 1559, it is a translation into English of an account of the lives and acts of the kings and princes of Wales from Cadwaladr to Llywelyn ap Gruffudd, the last native Welsh prince.

The antiquary and map-maker Humphrey Llwyd was born in Denbigh about 1527 and educated at the University of Oxford. He spent many years in the service of the earl of Arundel and served as MP for East Grinstead and later for Denbigh. Llwyd was credited with facilitating the passage of the Bill for the translation of the Bible and the Book of Common Prayer into Welsh. He died in Denbigh in 1568. Cronica Walliae, Llwyd's earliest and by far his largest extant work, was completed in 1559 but remained unpublished. In this essay, Llwyd presents what he regarded as the true history of Wales to readers outside its borders. Based on the medieval Welsh chronicle Brut y Tywysogyon, it is the first attempt to provide a history in English of the lives and acts of the kings and princes of Wales from Cadwaladr to Llywelyn ap Gruffudd, the last native Welsh prince. The Elizabethan scholar David Powel later used Cronica Walliae as the basis for Historie of Cambria (1584), which became the foundational work for the history of Wales. The text of this first ever edition of Cronica Walliae is based on the Llanstephan manuscript at the National Library of Wales, and the aim of the editor has been to reproduce Llwyd's original as far as it is possible to do so.