This is one of the oldest feasts, unique to the Order, that is on the Order's calendar. In his history of the Dominican Rite, Fr. William Bonniwell, O.P. notes that this feast is actually listed on the oldest surviving Dominican liturgical calendar, which dates back to the time when Humbert de Romans was Master of the Order.
The history of the feast is detailed in the third lesson of Matins:
"When Saint Louis, king of France, accepted from Baldwin II, emperor of Constantinople, the gift of the Lord’s crown of thorns, he sent to Constantinople two brethren, Stephen and James, of the Order of Preachers. In the year 1239, on the day following Saint Lawrence’s feast, they brought the crown to Sens, to the king. With great solemnity, it was borne to Paris and was finally placed in the royal palace, in a chapel built by Louis himself. The precious treasure, profanely stolen during the unhappy days of the French Revolution towards the end of the eighteenth century, was later restored and transferred to the metropolitan basilica. Louis however, made a gift of some thorns of the sacred crown to the Dominicans and commissioned them to celebrate, in the chapel dedicated to the crown, the anniversary of its reception there. The feast of the most holy crown of thorns was inserted into the calendar of the Order of Preachers about the middle of the thirteenth century."
