Peter Thomas was a successful churchman and crusading papal legate of the 14th century who began his career as an impoverished Carmelite friar and ended it as Latin patriarch of Constantinople. The Life of Peter Thomas, a biography written immediately after Peter's death by a devoted friend, Philippe de Mézières, who is himself an important figure in the history of the crusades, is not only the best source for the life of Peter Thomas, but an extremely valuable source for the history of the crusades, most importantly the attack on Alexandria in 1365 led by King Peter I of Cyprus.

The work also provides a wealth of other insights into the history of the Mediterranean of that period, including inter-faith relations in the kingdom of Cyprus, the relationship between the Latin and Orthodox churches, and the messy political struggles in Italy and surrounding areas. This translation of Philippe de Mézières' Life of Peter Thomas makes use of the best modern edition of the text, and as such is the first translation of what is the fullest surviving version of the Life. Additional material written by Philippe de Mézières has been selected and translated here for the first time to offer further insight into the two men and their activities in service of the crusade.

The translation makes this important text more accessible than ever before for students and others with an interest in the crusades and the Eastern Mediterranean in the later medieval period.