General map of the excavations that took place near the Rua de São Mamede, below the castle of the City of Lisbon

Drawing of the excavations carried out in the Rua de São Mamede in 1798, with the title in the centre. In the bottom right-hand corner is the signature of the architect Francisco Xavier Fabri, who oversaw the reconstruction of the city around the area where the Roman theatre was uncovered.

For a long time, Fabri was thought to be the one to have discovered the Roman Theatre. However, from documents found in the Brazilian National Library in Rio de Janeiro (Portugal Collection), we now know that Manuel Caetano de Sousa, also architect of the Casa Real (Royal House), was actually the first person to discover the site. Nevertheless, there is no doubt that this drawing, dated 1798, is his own. 

This was the first survey of the Roman Theatre to be conducted following its discovery, and the level of precision, exquisite detail and technical nature of the drawing, not to mention the beauty of the linework, offer up a treasure trove of information even today.