Traditionally the cult of St Thomas Becket has been associated with opposition to English kings. However, in the period between Henry II’s penance in Canterbury in 1174 and the political renewal of the cult following the 1220 translation overseen by Stephen Langton, the symbolic fortunes of Plantagenet kingship and the cult of St Thomas were entwined. My article explores this relationship from one particular angle: namely, an imperial one. Following Henry II’s accession, Plantagenet political culture had acquired a fresh imperial emphasis. Thomas Becket’s murder in 1170 challenged this emphasis, and called for a sudden reorientation in the crown’s relationship to sanctity. This reorientation was successful to some extent. In engaging with the cult of St Thomas, Henry II could provisionally claim the humble, peace-giving role of the ideal medieval king or emperor, a David or a Charlemagne.

Plantagenet models of kingship drew on the resources for an idealized empire that were developed in twelfth-century Germany. Martin Aurell has noted that Plantagenet royal ceremonies, in particular those of consecration and coronation, borrowed Romano-Germanic customs and materials. The Plantagenet crown was probably an imperial diadem, one of two brought over by the Empress Matilda in 1125. ‘A large crown which came from Germany’ was among regalia delivered to King John at Clarendon in 1207. Nonetheless, the symbolism and rituals of Plantagenet kingship tend to be represented by historians as secondary to the ruler’s practical power, at least in England, where sovereignty was accommodated by an exceptionally advanced administrative apparatus. By contrast, imperial lordship in the same period is usually understood to have been largely charismatic, with public displays of judicious peace-making compensating for the emperor’s inability to turn law-giving power into political power. Nonetheless, both Henry II and Frederick Barbarossa, in aiming to reacquire allegedly ancient rights and honours, sought to renegotiate the terms of secular and sacred power. Since Constantine, the emperor’s role as the fount of public law had been closely associated with the idea of the empire as a unification of political and religious bodies. Saints’ cults played an important role in twelfth-century projects of renovatio, in particular because they allowed imperial aspirations to be expressed without reference to practical political limitations or to canon law.