When Augustine was sent by Pope Gregory to Christianise England, in the time of the Romans, he was received and protected by Ethelbert, King of Kent, whose wife, daughter of Charibert, King of Paris, was a Christian, and did much for Augustine.
She founded a nunnery in memory of Columba, which was named _Sedes misericordioe_, the House of Mercy, and, as the region was Mercian, the two names became involved.

As Columba is the Latin for dove, the dove became a sort of signification of the nunnery.

She seized on the idea and made the newly-founded nunnery a house of doves.

Someone sent her a freshly-discovered dove, a sort of carrier, but which had in the white feathers of its head and neck the form of a religious cowl.

The nunnery flourished for more than a century, when, in the time of Penda, who was the reactionary of heathendom, it fell into decay.