A singular ancient Pavian custom was connected with this church. Once a year a kind of fair was held there, at which nothing was sold but rings, and no one was allowed to buy them except children and unmarried women. It is thought that the custom was begun by Gundeberg herself in commemoration of the gift of three rings, one with a pearl, and two with jacinth stones, from Gregory the Great.[31] His letter of congratulation to Theodolinda on the baptism of her little son Adaloald is still existing. He says "he sends some gifts for her boy, and three rings for her young daughter Gundeberg." Possibly the gift of the Pope was placed in the treasury of the church, and commemorated at first by the sale of blessed amulets in the form of rings, but which afterwards degenerated into a fair. The custom lasted till 1669. Industries of all kinds seem to have flourished under the Longobards; and the Popes of Rome and other sovereigns made frequent use of Lombard artificers. A letter from Gregory to Arichi, Duke of Lombardy, dated 596, asks him to send workmen and oxen to Brescia, to cut down and cart to Rome some trees for beams in the church of SS. Peter and Paul, promising him in return a _dono che non sarà indegno di voi_ (a gift not unworthy of you).[32] In A.D. 600, Cacanus, King of the Avari (Huns), sent to Agilulf for marine architects and workmen to build the boats with which Cacanus took a certain island in Thrace.[33] As for the Comacine Masters at home, they had plenty of church-building. The seventh and eighth centuries were times of great devotion to the Church, and consequently a great church-building era. King Luitprand realized this so strongly that he added to the laws of Rotharis, a clause permitting his subjects to make legacies to the Church _pro remedio animæ suæ_; a law, by the way, which was not always healthy in its action; for it permitted the evil-disposed to indulge in crimes during their lifetime, and then, by defrauding their natural heirs of their inheritance, to secure, as they believed, their souls against eternal punishment, by leaving funds for building a church or a monastery. [Illustration: COMACINE CAPITAL IN SAN ZENO, VERONA. DRAGONS, INTERLACED. _See page 43._] The will of Eriprand, Duke of Cremona, dated 685, is still extant, with a legacy to the churches of S. Maria Maggiore, and S. Michele in Borgo, of that city. Pope Sergius I. restored the Basilica of Ostia, and founded S. Maria in Via Lata, giving them rich gifts, and Pope John II. repaired and endowed S. Maria in Trastevere.[34]