Troubadour poetry, though not widely read in English, has had a profound impact on modern Western art in general, and particularly love poetry. Modern notions of idealized romantic love can be traced back to a certain extent to the Troubadour love poets in southern France in the 1200s.
The Troubadours lauded love, especially the sweet pain of unattainable love, as embodied by an idealized Lady. They were the poets of the courtly love.
Modern commentators often miss the sacred dimension to Troubadour poetry and the path of courtly love. It's a pity that modern audiences tend to read Troubadour poetry as if it was a lot of lovesick romantic poetry. Much of Troubadour poetry, though couched in romantic or even sexual imagery, is truly sacred poetry, emerging from a genuine mystical tradition.
The Troubadours emerged in southern France at the height of the Albigensian Cathar movement and immediately following their slaughter in the Albigensian Crusade. Many of the Troubadours may have themselves been Cathars or at least influnced by Cathar notions. The Cathars were a gnostic group of Christians who rivaled the Catholic Church in Southern France and other parts of Europe, until they were declared heretical and ultimately driven underground. The Cathar Elect were celibate vegetarians who upheld notions of non-violence, reverence for the natural world (with special focus on the sun and the moon), and the spiritual equality of women. While some aspects of Cathar spirituality had a world-denying quality that might be unappealing to the New Age notions of today, the Cathars were a vibrant group with a rich mystical and spiritual heritage. There have even been suggestions of links between the Cathars and Sufi groups in Spain and Palestine.
Troubadours were court poets, singers, and composers, often in the employ of Cathar nobles and rulers.
Courtly love is often thought of as a strange societal pattern that occurred because marriage among the wealthy was a practical affair brokered between families, leaving little room for love. That may have added to the appeal of courtly love, but it doesn't really explain it. Let me say this directly: Courtly love was a conscious spiritual practice. The ideal in courtly love was to embody the archetypal forces of Lover and Beloved.
The Beloved was usually the woman. She was to embody the ideal of the Divine Feminine, Sophia, Divine Wisdom. She was to be ever slightly out of reach, but within sight. Her presence was to draw the Lover with her presence, her goodness, her feminine divinity. She was to be a beacon. In striving to embody this for her Lover, she was to merge with the Divine she embodied.
The Lover was usually the man. His was the more active role. He was to seek his Beloved, his idealized Lady. He had to prove himself worthy of her, face great obstacles with humility and perserverance, in her name. In the Lover's intense passion for his Beloved, his constant focussing on her, he was to ultimately become a perfect Lover of the Divine and unite with the divinity he saw embodied in his Beloved.
The goal of courtly love was not sexual intimacy. Indeed, sex was avoided because it would satiate the longing that acted as the spiritual force that drew the man and woman as Lover and Beloved to the goal of spiritual marriage. This was the ideal, and certainly not every couple followed this path, nor did every Troubadour always celebrate the inner sacred meaning of the path. Yet this was the core, and it was a pathway taught through societies and particularly passed on through Troubadour poetry and song. Courtly love should be seen as genuine spiritual pathway and not be superficialized. It is not inappropriate to think of courtly love as similar to Tantric sexual spirituality, as developed in India.
Troubadours were also to some degree influenced by the great Arab poetry, and especially the Sufi poetry, flowing in through Moorish Spain, the trade routes of North Africa, and Palestine and the Crusaders interacted with the Muslim world there. The Beloved of the Troubadours is the same Divine Beloved of the Sufis. When reading Troubadour poetry, as with Sufi poetry, the Beloved -- though she may also be a real person -- should be understood to be the Divine and no other.
Ultimately, the Cathars were declared a heretical sect by the Catholic Church and they were brutally suppressed. The Troubadours scattered, but their influence continued with the many related poetic/mystical traditions that emerged from their diaspora: the Trouveres in norther France, the Minnensingers in Germany (including Wolfram von Ehrenbach, author of the first Grail romance), the Fideli di Amore in Italy (including Dante).
St. Francis of Assissi himself was a great lover of French Troubadour songs and traditions. Though he lived and taught within the Catholic Church, elements of Cathar and Troubadour spirituality can be seen in his own radiant ministry: his love of nature (particularly the sun and the moon), his vision of a divine woman, and his relationship with St. Clare (which was very much in the tradition of the chaste Lover-Beloved relationship.)