From Discovery.com:

Two brothers are behind Rome's greatest monuments, according to Italian archaeologists who have discovered two furnaces that provided the bricks for buildings such as the Colosseum and the Pantheon.

Found in Mugnano in Teverina, a tiny village some 80 kilometers (50 miles) north of Rome, the furnaces belonged to Tullus and Lucanus, brothers of the Domitii family, as an inscription found on the road leading to the brickfield confirms: "iter privatum duorum Domitiorum" (private road of the two Domitii).

The furnaces provided bricks for grandiose buildings such as the Colosseum, the Pantheon, the Market of Trajan and the Diocletian and Caracalla Baths, said archaeologist Tiziano Gasperoni, who discovered the furnaces.

"The bricks used to erect these building all bear the same maker's marks. At the Domitii furnaces we found more than 100 of these marks, so there is no doubt that the site at Mugnano provided bricks to build Rome’s most important monuments," Gasperoni told Discovery News.

Marks were a peculiar feature of kilns. Each Roman brickmaker had his own — circular, rectangular or moon-shaped. The mark contained his own name, often with the name of the place or the owner of the brickfield.

Half-moon-shaped, the Domitii brothers mark featured the name of the worker responsible for the kiln — Titus Greius Ianuarius — the name of the brickfield and the name of Tullus and Lucanus.

According to Piero Alfredo Gianfrotta, who teaches ancient topography at the Tuscia University in Viterbo, the furnaces at Mugnano represent an important discovery as they are the only known example of a brickfield destined to provide raw material for Rome's most significant buildings.

Besides bricks and tiles, the Domitii furnaces were also specialized in the production of doli, big containers in terracotta which were buried up to their necks to preserve wine and olive oil, and mortars to grind seeds, herbs and nuts into meal.

"Mortars and doli with the Domitii mark can be found throughout the Mediterranean, mainly in France, Spain and North Africa," Gasperoni said.

Mugnano was an ideal spot for furnaces. It was rich with some of the best clay and had an abundance of water and wood. Moreover, it was close to the river Tiber.

"Bricks and terracotta containers were loaded on large boats and carried to Rome through the Tiber. International trade was also possible because of the Ostia harbor," Gasperoni said.

The Domitii were a noble and well-connected family throughout the first and early second centuries. Indeed, one of its members, Domitia Lucilla Minor, was the mother of the future emperor Marcus Aurelius.

Settled around the first half of the 1st century A.D., the furnaces remained the property of the Domitii family for more than a century. They were then inherited by emperor Marcus Aurelius and remained the emperor’s property until brick production ended in the 4th and 5th centuries A.D.