This book on the language of love’s joy starts with the acknowledgement that such a language has repeatedly been expressed as impossible. The poetic and vernacular tradition of joie d’amour originates in the lyrics of the troubadours, which famously sing the absence of fulfilment in the endless prolongation of desire: it is thus born in a lyrical language that presupposes its impossibility. This study on the language of love’s joy is thus grounded in the paradox that love’s joy is beyond language. The elusive nature of the emotion has resulted in a lack of studies on love’s joy. If there is an important scholarly tradition on the semantics of Old Occitan joi, this critical interest has been confined to the French literature of the twelfth and thirteenth centuries and has not been picked up by the field of emotion history nor by more recent studies on medieval love literature.