The Collaborative International Dictionary of English v.0.48:

Courtliness \Court"li*ness\ (-l?-n?s), n. [From Courtly.]
   The quality of being courtly; elegance or dignity of manners.
   [1913 Webster]

WordNet (r) 3.0 (2006):

courtliness
    n 1: elegance suggestive of a royal court

Moby Thesaurus II by Grady Ward, 1.0:

59 Moby Thesaurus words for "courtliness":
   amenities, augustness, chivalrousness, chivalry, civilities,
   civility, comity, convention, courtly politeness, decencies,
   decorum, dignifiedness, dignity, diplomatic code, elegance,
   elegancies, etiquette, exquisite manners, formalities, gallantness,
   gallantry, good form, good manners, grandeur, gravity, kingliness,
   knightliness, loftiness, lordliness, majesty, manners, mores,
   natural politeness, nobility, noblesse oblige, point of etiquette,
   politeness, politesse, pride of bearing, pride of place,
   princeliness, proprieties, protocol, proud bearing, punctilio,
   quiet good manners, regality, rules of conduct, sedateness,
   sobriety, social code, social conduct, social graces,
   social procedures, social usage, solemnity, stateliness,
   venerability, worthiness