Short answers, pulled from the story.
Courtly love began to be cultivated around the year 1099. Eleanor of Aquitaine moved from southern France to become queen-consort of France and later queen of England while carrying these ideals with her.
Andreas Capellanus published his work De amore by the late twelfth century. He listed specific rules stating that marriage was no excuse for not loving another person, jealousy was necessary for true love, and no one could be bound by double love simultaneously.
One theory suggests Arabic poetry in Al-Andalus influenced courtly love traditions in southern France. Ibn Hazm wrote The Ring of the Dove emphasizing restraint and chastity while Ibn Arabi composed The Translator of Desires around the same time as early troubadour songs.
No historical records offer evidence of courtly love existing in real life outside literature. Historian John F. Benton found no documentary proof in law codes or chronicles and later historians noted none of the abundant letters or songs suggest they ever existed outside poetic literature.
Provençal poets began writing lyric poems about courtly love during the eleventh century. Walther von der Vogelweide and Wolfram von Eschenbach carried this tradition into German Minnesänger poetry while Dante and Petrarch later incorporated these themes into their own works.