The most important object kept in the chapel of the Treasure is the great monstrance. Enrique de Arfe labored on it from 1517–1524, on commission to Cardinal Cisneros. It is of archaic Gothic design. Initially made of silver by the 16th century Archbishop Quiroga commissioned that it be plated in gold, to match the gold plated wood of the monstrance of the altar.
Cardinal Cisneros wanted a monstrance of greater presence and importance than that of Isabella the Catholic to show it off in the procession of the Corpus Christi of Toledo, the most important that was celebrated in Castile. The monstrance took seven years to create and its cost surpassed 15 million maravedís, which Arce received, including the stipulated 2,700 reales, a bonus of 2,500 maravedís that the cathedral's chapter presented to him on Christmas of 1523, having been impressed by his work.
The monstrance has a hexagonal ground plan. It rises with small columns which are exquisitely made, with adornments of gems and varied figurines of angels, saints, fleurons, small bells and clappers. The work encloses in the last section where a cross of the 16th century is located. The pedestal on which it sits is Baroque of the 18th century.
In Toledo, it is by custom, since the year 1595, to carry out this monstrance in the procession of the Corpus Christi, on a float made for this purpose with an adjustable leveling which is mechanically activated. In the procession, ahead of the monstrance the political and ecclesiastical authorities and behind are the cadets of the Infantry Academy.
Curious facts: The monstrance is built with the help of 12,500 bolts which secure it, 5,600 diverse pieces and 260 figurines. 183 kg of silver and 18 of gold were used. Among the recorded inscriptions on it, can be read:
"Don Francisco Jiménez [Cardinal Cisneros], Cardinal Archbishop of Toledo, Governor of Spain and conqueror of Africa, commissioned this monstrance of the Most Holy Body of Christ to be made, which was finished during the vacant see, being worker Diego López de Ayala. Year of the Lord 1524."