He is among the names of the kings who according to an ancient saying , were avenged by the slaying of Penda in 654 .
In this way Sigeberht became a Christian martyr .
Sigeberht is among the names of the kings who according to an ancient saying , were avenged by the slaying of Penda in 654 .
In this way Sigeberht became a Christian martyr .