Characteristic as the construction of the limestone atriums is, it is difficult to determine to what age they belong. The beginning of the period cannot be determined even approximately. The end, however, is fixed by the earlier limit of the next period, the Second Punic War. We may, therefore, assign the houses with the limestone atriums to a period just preceding this war; reckoning in round numbers, they were built before 200 B.C.

In the third, or Tufa Period, came the climax of the development of Pompeian architecture prior to the Roman domination. The favorite building material was the gray tufa.

With the exception of the Greek temple mentioned above, all the public buildings of Pompeii that do not belong to the time of the Roman colony have a homogeneous character; a list of them would include the colonnade about the Forum, the Basilica, the temples of Apollo and of Jupiter, the Large Theatre with the colonnades of the Forum Triangulare and the Barracks of the Gladiators, the Stabian Baths, the Palaestra, and the outer part of the Porta Marina with the inner parts of the other gates. Closely associated with these public edifices is a large number of private houses; as a specially characteristic example, we may mention the house of the Faun.

All these buildings are similar in style and construction; they evidently date from a period of great building activity. It must also have been a period of peace and prosperity; for the whole city, from the artistic and monumental point of view, underwent a transformation. Certain Oscan inscriptions, an early Latin monumental inscription, and a few words, dating from 78 B.C., scratched upon the plaster of the Basilica, oblige us to place the Tufa Period before the time of the Roman colony; yet not long before, for the next oldest buildings date from the first years of the colony. The time of peace that furnished the background for the period can only have been that between the Second Punic War and the Social War, about 200 to 90 B.C.; the Tufa Period was approximately the second century before Christ.

In marked contrast with the Period of the Limestone Atriums, the Tufa Period has a pronounced artistic character. It is preëminently a period of monumental construction. Buildings and public places are adorned with colonnades of the Doric, Ionic, and Corinthian orders. The simple and beautiful forms of the Greek architecture are used, sparingly indeed, but without petty detail and with evident fear of excessive ornamentation. Columns and architraves are white, with only slight suggestion of the earlier Greek polychrome decoration. A variety of color, however, is laid on the walls, and with this period the history of Pompeian wall decoration begins.

The Tufa Period coincides throughout with the time of the first style of decoration. This, known as the Incrustation Style, aimed to imitate in stucco the appearance of a wall veneered with colored marbles. Wall paintings are wholly lacking, but pictures, often of rare beauty, are found in the mosaics of the floors. In this period, we may truly say that Pompeian architecture was at its best. With it the pure Greek tradition dies out; all the buildings of later times bear the Roman stamp.

The buildings of the Tufa Period are easily recognized by the unobtrusiveness of the materials used in their construction. The rubble work is mostly of lava; but gray tufa was used exclusively, not only for ashlar work in façades, but also for columns and entablatures. The surface of the tufa was coated with a layer of fine white stucco, which gave it the appearance of marble. The use of marble for building purposes, however, is foreign to this period; and it speaks well for the culture of the Oscan Pompeians that they had pleasure in beauty of form above richness of material.

The fourth period covers the earlier decades of the Roman colony, from 80 B.C. to near the end of the Republic. According to inscriptions which are still extant, soon after the year 80 a wealthy colonist, Gaius Quinctius Valgus, when duumvir with Marcus Porcius as colleague, built the Small Theatre, and afterwards, when quinquennial duumvir with the same colleague, the Amphitheatre also. Both structures have the quasi-reticulate facing ([Fig. 11]); and several other buildings in which the same style of masonry is found without doubt belong to the same period—the Baths near the Forum, the temple of Zeus Milichius, a building just inside the Porta Marina, and apparently the hall at the southeast corner of the Forum, which we shall identify as the Comitium; with these should be included also the original temple of Isis, which was destroyed by the earthquake of 63 A.D. Few houses dating from this period have been discovered; the provision made by the preceding period in this respect had been so generous that new houses were not needed.