El Mahdi
Muad'Dib of the Anauroch
I thought D&D Clerics were originally based on Knights Templar and Hospitaller, while Paladins were based on Charlemagne and some other sources.
AFAIK, No. The only real aspect that comes from Charlemagne is the name, and the use of Roland (Orlando) as one of the models for the Paladin Class. Roland though is really the only one of Charlemagne's Peers that truy resembles the D&D Paladin (the Paragon of the Archetype). Though the list of the peers varied from author to author, and the various lists included other Knights (but none with a comparable adherence to Knightly and Christian Virtues as Roland), they also included as "Paladins": Ogier the Dane (a Norse Pagan/Barbarian Warrior converted to Christianity); Archbishop Turpin (a Priest); Fierabras (a Saracen Warrior converted to Christianity); Ganelon (the Evil Knight that betrays Charlemagne and the Peers); and Maugris the Sorcerer.
Actually, Clerics are more based on the Fighting Priest archetype of Archbishop Turpin (one of Charlemagne's Paladins) than they are Mendicant Crusading Knights, and is where the idea of using weapons that don't draw blood comes from (such as Clubs, Maces, etc.)*. Templars and Hospitalers most certainly used swords, and predominantly so.
Though to be honest, even the original roots of these classes were a bit muddled, with a little bit of this and a little bit of that, and both dipping from some of the same sources. Paladins had aspects of Charlemagne's Knights, the Knights of King Arthur, etc., as well as aspects of Crusading Templars Clerics were similar to Templars, except for the use of bludgeoning weapons only, and the addition of turning undead (which comes from other sources entirely).
*...which by the way, is absolutely silly. Maces left behind horrific wounds, which most certainly drew blood. By comparison, a sword left behind realtively clean wounds (though very lethal).

