Baldwin was the possessor of a treasure which fascinated the imagination of the Christians of those days--the crown of thorns worn by Christ during His passion. He had pledged it at Venice as a security for a considerable loan from the Venetians, and he now offered to make it over to Louis in return for efficient help either in men or money. Louis accepted the offer with rapture. Not long before he had been greatly alarmed at the reported loss of another precious relic, one of the nails said to have fastened the body of our Lord to the cross. It had been deposited in the Abbey of St. Denis, and disappeared one day during a religious ceremony. When it was found, Louis said: 'I would rather that the earth had opened and swallowed up one of the chief cities of my kingdom than have lost it.' He took every care to avoid the disgrace which would attend any kind of traffic in so sacred a matter, and ultimately obtained the crown of thorns for a sum which, including all expenses, would equal about 54,000_l_. of our money. [Footnote 14] [Footnote 14: 12,000 livres Parisis, about 1,350,000 francs in modern French money. The French _livre_ (like the English _pound_) was formerly a pound's _weight_ of silver. Charlemagne ordained that a silver sou should be precisely the twentieth part of twelve ounces of silver, and in this way twenty sous came to be looked upon as a livre. Both weight and value have been very greatly reduced in the course of time. Again, the weight of the livre, and consequently its value, varied in different parts of France. The _livre Parisis_ was the livre of Paris, the _livre Tournois_ (p. 19) the livre of Tours, &c.] {50} We cannot, in the present day, sympathise with the eager credulity which Christian faith does not require and sound criticism entirely condemns; but we ought to and we can understand it in an age when men contemplated every fact and every tradition of the Gospel with a deep, poetic faith, and when the belief that they were in the presence of any fragment or relic of sacred times was sufficient to call forth emotion and reverence as deep as their faith. It is to such feelings that we owe one of the most perfect and graceful monuments of the Middle Ages, the Sainte Chapelle, built by Louis between 1245 and 1248, to contain the precious relics which he had accumulated. The architect, Pierre de Montreuil, comprehended and glorified the piety of the King in a marvellous manner, and no doubt his own genius was kindled by the same strong religious feeling which animated St. Louis. {51} Chapter VII. Origin Of The Passion Felt By St. Louis For The Crusades. His Sickness In 1244. His Vow. His Departure On His First Crusade In 1248.