Allan

Allan is an anglicised form of the Celtic name Alan, whose exact root is debated but is most often linked to a Breton or Old Welsh element meaning rock or harmony. The name was brought to England by Breton followers of William the Conqueror after 1066, helping establish it across the British Isles. It is common as a surname as well as a given name, and the Scottish and Scandinavian spelling Allan became particularly widespread. Related forms include Alan, Allen, and the Breton Alain.