What's the difference between i.e. and e.g.?
early 13c., from Old French chapele (12c., Modern French chapelle), from Medieval Latin cappella "chapel, sanctuary for relics," literally "little cape," diminutive of Late Latin cappa "cape" (see cap (n.)); by tradition, originally in reference to the sanctuary in France in which the miraculous cape of St. Martin of Tours, patron saint of France, was preserved; meaning extended in most European languages to "any sanctuary." (While serving Rome as a soldier deployed in Gaul, Martin cut his military coat in half to share it with a ragged beggar. That night, Martin dreamed Christ wearing the half-cloak; the half Martin kept was the relic.)
a holy place or sanctuary, occurs only in Amos 7:13, where one of the idol priests calls Bethel "the king's chapel."
small, intimate place of worship. The name was originally applied to the shrine in which the kings of France preserved the cape (late Latin cappella, diminutive of cappa) of St. Martin. By tradition, this garment had been torn into two pieces by St. Martin of Tours (c. 316-397) that he might share it with a ragged beggar; later Martin had a vision of Christ wearing the half cape, and it was preserved as a relic and carried about by the Frankish kings on their military campaigns. By extension, any sanctuary housing relics was called a chapel and the priest cappellanus, or chaplain. By a further extension, all places of worship that were not mother churches, including a large number of miscellaneous foundations, came to be known as chapels. Oratories, places of private worship attached to royal residences, also were termed chapels. Thus the Sainte Chapelle (1248), the palace chapel at Paris, was built by St. Louis IX to enshrine the relic of what was thought to be the Crown of Thorns, which he had brought from Constantinople. In the next century, other saintes chapelles were founded by princes of the French royal house at Bourges, Riom, and elsewhere.