This precious silver box was created to contain a relic of the martyred English saint Thomas Becket. Saint Thomas was the archbishop of Canterbury from 1162 to 1170, and he is perhaps best known for his struggles with King Henry II of England over the separation between the rights of the monarch and the rights of the church. Thomas was killed by four knights of Henry's court in Canterbury Cathedral at twilight on December 29, 1170.
The long sides of the reliquary display a brief narrative of the saint's martyrdom. On one side, the lower rectangular panel shows the four knights assaulting Thomas, while on the triangular lid above, an angel makes a sign of blessing over the event. On the other side, the lower panel shows Thomas's body lying in state, while above, an angel cradles a small child, the symbol of the saint's soul as it rises to heaven. This reliquary is dated to the years immediately following Thomas's canonization in 1173, making it one of the earliest objects commemorating his sainthood.