Martyrdom of Ælfheah in Greenwich, England.

lfheah (c.953 19 April 1012), more commonly known today as Alphege, was an Anglo-Saxon Bishop of Winchester, later Archbishop of Canterbury. He became an anchorite before being elected abbot of Bath Abbey. His reputation for piety and sanctity led to his promotion to the episcopate and, eventually, to his becoming archbishop. lfheah furthered the cult of Dunstan and also encouraged learning. He was captured by Viking raiders in 1011 during the siege of Canterbury and killed by them the following year after refusing to allow himself to be ransomed. lfheah was canonised as a saint in 1078. Thomas Becket, a later Archbishop of Canterbury, prayed to him just before his own murder in Canterbury Cathedral in 1170.

A martyr (Greek: μάρτυς, mártys, "witness", or μαρτυρία, marturia, stem μαρτυρ-, martyr-) is someone that suffers persecution and death for advocating, renouncing, or refusing to renounce or advocate, a religious belief or cause as demanded by an external party. In the martyrdom narrative of the remembering community, this refusal to comply with the presented demands results in the punishment or execution of an actor by an alleged oppressor. Accordingly, the status of the 'martyr' can be considered a posthumous title as a reward for those who are considered worthy of the concept of martyrdom by the living, regardless of any attempts by the deceased to control how they will be remembered in advance. Insofar, the martyr is a relational figure of a society's boundary work that is produced by collective memory. Originally applied only to those who suffered for their religious beliefs, the term has come to be used in connection with people killed for a political cause.

Most martyrs are considered holy or are respected by their followers, becoming symbols of exceptional leadership and heroism in the face of difficult circumstances. Martyrs play significant roles in religions. Similarly, martyrs have had notable effects in secular life, including such figures as Socrates, among other political and cultural examples.