it is of German origin

Heartily wielding the formidable family motto of "Firm in Adversity!", the continually and colorfully distinguished brave, proud, and noble Scottish surname of Mann strides boldly forth through the gathering mists of time from its' origins in the historic county of Aberdeenshire- where they had held a family seat during the most ancient of times.

Deriving from the descriptive pronoun "man", the surname "Mann" carries the meaning of "man", "person", or "husband".

Manning is an English patronymic name for Mann which means fierce or strong man.

Wielding the mighty family motto that translates into "Firm in adversity!", the proud and noble Scottish surname of Mann strides through history from the Strathclyde-Briton people of the Scottish/English Borderlands. First found in the historic county of Aberdeenshire in the northeast of Scotland, they held a family seat from ancient times.

Perhaps after migration, but it seems to have started in Scotland or Germany.

Please see the related link below for more information: