Final answer:
The Pantheon in Rome was traditionally thought to be built by Emperor Hadrian, but recent evidence suggests Emperor Trajan may have substantially designed it, with the work completed under Hadrian; Apollodorus of Damascus is a possible designer.
Step-by-step explanation:
The emperor responsible for the construction of the Pantheon in Rome is a subject of historical debate. Originally attributed to Emperor Hadrian, recent evidence suggests that the substantial groundwork and design of the Pantheon may have been initiated under Emperor Trajan. The confusion originates from an inscription attributing the Pantheon to Agrippa, and the reinterpretation of construction materials dating from the reign of Trajan. However, the building was completed under Hadrian, and it served as a representation of the divine authority of the emperors. Apollodorus of Damascus is a potential designer of the Pantheon, as he was Trajan's favored architect and well versed in Roman architecture and engineering.