Everywhere conspicuous in accounts of medieval Italian political alignments, the term Guelph denotes, broadly speaking, allegiance to the Pope, and Ghibelline allegiance to the Holy Roman Emperor as regards protection, patronage, rights, privileges and immunities within the complex communal life of the time. They first appear in Florence in the 1240s but go back to the rivalry in the twelfth century between the German dynasties ranged with or against the Hohenstaufen, the term ‘Guelph' deriving from the Welf family of Bavaria and the term ‘Ghibelline' from Waiblingen, a Hohenstaufen castle and stronghold. …
Took, John. "Guelphs and Ghibellines". The Literary Encyclopedia. First published 15 May 2006; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1668, accessed 28 April 2015.]