== Litteratur ==
* Abulafia, David. ''Frederick II. A Medieval Emperor'', Allen Lane the Penguin Press, 1988, 466pp {{ISBN|88-06-13197-4}}
* Armstrong, Karen. ''Holy War – The Crusades and Their Impact on Today's World'', (Anchor Books, 2nd ed. 2001), {{ISBN|0-385-72140-4}}.
* Barraclough, Geoffrey. ''The Origins of Modern Germany'' Norton, second edition, Norton, 1984 (2d ed. publ. 1947), {{ISBN|0-393-30153-2}}.
* Cavendish, Richard. "Death of the Emperor Frederick II," ''History Today,'' Dec 2000, Vol. 50, Issue 12
* Davis, R.H.C. ''A History of Medieval Europe'', Longman, 2nd ed. 1988, {{ISBN|0-582-01404-2}}.
* Klaus van Eickels: ''Friedrich II.'', i: Bernd Schneidmüller/Stefan Weinfurter (editors): ''Die deutschen Herrscher des Mittelalters, Historische Porträts von Heinrich I. bis Maximilian I.'', Munich 2003, p.&nbsp;293-314 and p.&nbsp;585 (Bibliography). En fremragende kort biografi. Van Eickels har også redigeret en bog med kildemateriale om Frederik 2. I.
* Kantorowicz, Ernst. ''Frederick the Second, 1194-1250'' (English edition 1957), standardværket om Frederik.
* Maalouf, Amin. ''The Crusades Through Arab Eyes'', Schocken, 1989, {{ISBN|0-8052-0898-4}}.
* Masson, Georgina. ''Frederick II of Hohenstaufen'', Martin Secker & Warburg, 1957, {{ISBN|88-452-9107-3}}
* Powell, James M.. "Church and Crusade: Frederick II and Louis IX," ''Catholic Historical Review,'' April 2007, Vol. 93 Issue 2, pp 251–264
* Wolfgang Stürner: ''Friedrich II. (Gestalten des Mittelalters und der Renaissance)'', 2 volumes, Darmstadt 1992-2000. Den bedste biografi om Frederik 2. Sober og objektiv, med omfattende litteraturliste. 
* Trimboli Editori (forlag): ''Castel del Monte. The extraordinary tale of Frederick II, King of Sicily and Roman-German Emperor.'' Trimboli 2009, {{ISBN|978-88-89503-63-8}}
* Gunther Wolf (editor).: ''Stupor mundi. Zur Geschichte Friedrichs II. von Hohenstaufen (Wege der Forschung 101)'', 2. veränderte Aufl., Darmstadt 1982. En vigtig samling essays om Frederik 2.
Religion Walhalla