Frate Melano, Operaio of the Duomo, and Maestro Niccolò Pisano for the work of the pulpit (Sept. 29th, 1266), and the assignment of the tavola of the high altar to Duccio di Buoninsegna (Oct. 9th, 1308). Here, too, are shown the documents of the last days of the once mighty Republic--"Il Governo della Difesa della Libertà Senese ritirato in Montalcino"--down to the surrender of that last stronghold of Sienese liberty. There is, further, a whole collection--of the utmost interest to students of Dante--of documents illustrating the _Divina Commedia_, with the Will, _testamento_, of Messer Giovanni Boccaccio of Certaldo. Even more interesting than these, and absolutely unique of its kind, is the collection of _Tavolette dipinte della Biccherna e della Gabella_, the painted covers of the Treasury Registers of the Republic of Siena, which "offer a true museum of exquisite paintings, which is likewise a history of national sentiment [_del sentimento cittadino_], from Don Ugo, monk of San Galgano, seated at his desk of the Biccherna to regulate accounts and taxes with the feudatories, to the allegory of the sufferings endured during the last, heroical siege."[143] The officers of the Biccherna--Camarlingo and four Provveditori--administered the revenues of the State; the officers of the Gabella--Camarlingo and three, afterwards four, Esecutori--were mainly concerned with the collection of taxes. Every six months a fresh set of Provveditori and Esecutori came in, fresh registers were begun, and at the end of the year the retiring Camarlinghi of Biccherna and Gabella (and sometimes the other officials) had the covers of the books of their term of office painted with their arms and those of their colleagues, and with either their portraits or some religious or allegorical device, or with the representation of one of the chief political events of the past year. This lasted until long after the fall of the Republic; but by that time the old book covers had been replaced by regular pictures, but still, to show their origin, marked with the arms of the Camarlinghi and their colleagues. Here I need enumerate only those _tavolette_ or _tavole_ that are more important, historically or artistically. For the registers of the Biccherna in 1258, two years before Montaperti, we have the portrait (by Gilio di Pietro) of Don Ugo the Camarlingo, who was re-elected repeatedly, and whom we have already met in connection with the cession of Montepulciano to the Republic. Later on we frequently find the arms of the Podestà, and also the portrait of the Scrittore, or scribe, who had to make the entries as the Camarlingo dictated. For the Gabella of 1344, when the rule of the Nine was nearing the end of its triumphant course, we have the Government of Siena enthroned over the Lupa, painted by Ambrogio Lorenzetti; for the Biccherna of 1385, after the fall of the Riformatori and the establishment of the new Monte del Popolo, there is a similar allegory