Hadrian spent much of his reign traveling about the Roman Empire and checking into the well - being of the cities, towns, provinces, and ordinary citizens over whom he ruled. He was always interested in civic improvements, and would often have a new bridge, road, aqueduct, or temple built when he thought that the local citizens would benefit by such new construction. The reign of Hadrian at the height of the PAX ROMANA period was a time of great peace and prosperity in the Roman Empire. He continued the public works building projects that his adoptive father Trajan began and strengthened the defenses on the borders of the empire. Because of attacks on Roman citizens living in southern Britain, he built Hadrian's Wall across a narrow part of the island. Hadrian was an educated emperor and a patron of the arts. He spent most of his reign visiting the different provinces of the empire and personally overseeing the improvements and public works carried out under his orders. Like Trajan and Nerva before him, he adopted a grown man in order to make him heir to the throne. When his first adopted son Aelius Caesar died of illness, Hadrian adopted another, Antoninus Pius, who would succeed him when Hadrian died in his bed after a long illness.