This book explores the formation of Catherine of Lancaster (1373-1418) and her arrival in Castile, linking that to the new interest in collecting and writing court poetry and the new production of religious lyric at her court. This book introduces a Castilian Queen of English extraction to contribute to the growing field of queenship and the influence of powerful women. Relatively little is known about Catherine from an English perspective. How she might have influenced court poetry and its production is only beginning to be explored, and this book marks an important contribution to that project in the way it enhances understanding of possible areas of influence from one country's religious production to another. It also addresses whether and in which ways Catherine might have influenced the development of a new court culture of poet-administrators, similar to the one she had left behind in England.  Lesley Twomey is Professor at Northumbria University, UK.