The archaeological remains of the Roman colony of Emona from the 4th and early 5th centuries point to a period of prosperity in the 4th century, a time of renewed infrastructure and new building development in several locations across the city, reinforcements to the city’s defence system, and in the second half of the 4th century there was also considerable investment in Christian buildings. At the same time, secular monuments and, in some cases, infrastructure such as the city moat and the cloacae were often abandoned or neglected. These changes were closely linked to a range of factors, an important one being the rise of Christianity. With the ongoing Christianisation of Emona, a diocese from the 4th century, the character of urban life was gradually transformed, as well as city’s appearance