The office was generally held by young men intending to follow the cursus honorum ("honors race") to high political office, traditionally after their quaestorship but before their praetorship. It was not a compulsory part of the cursus, and hence a former quaestor could be elected to the praetorship without having held the aedileship. However, it was an advantageous position to hold because it demonstrated the aspiring politician's commitment to public service, as well as giving him the opportunity to hold public festivals and games, an excellent way to increase his name recognition and popularity.
They were created in the same year as the Tribunes of the People (494 BC). Originally intended as assistants to the tribunes, they exercised certain police functions, were empowered to inflict fines and managed the plebeian and Roman games. Their duties at first were simply ministerial. They were the assistants to the tribunes in whatever matters that the tribunes would entrust to them, although most matters to which they were entrusted were of minimal importance. Around 446 BC, they were given the authority to care for the decrees of the senate (senatus consulta). When a senatus consulta was passed, it would be transcribed into a document, and depositied in the public treasury, the Aerarium. They were given this power because the Roman Consuls, who had held this power before, arbitrarily suppressed and altered the documents. They also maintained the acts of the Plebeian Council (popular assembly), the "plebiscites". Plebiscites, once passed, were also transcribed into a physical document for storage. While their powers grew over time, it is not always easy to distinguish the difference between their powers, and those of the Roman Censors. Occasionly, if a Censor was unable to carry out one of his tasks, an Aedile would perform the task instead.
According to Livy (vi. 42), after the passing of the Licinian rogations in 367 BC, an extra day was added to the Roman games; the aediles refused to bear the additional expense, whereupon the patricians offered to undertake it, on condition that they were admitted to the aedileship. The plebeians accepted the offer, and accordingly two curule aediles were appointed--at first from the patricians alone, then from patricians and plebeians in turn, lastly, from either--at the Tribal Assembly under the presidency of the consul. Curule Aediles, as formal magistrates, held certain honors that Plebeian Aediles (who were not technicaly magistrates), did not hold. Besides having the right to sit on a Curule Chair (sella curialis) and to wear a toga praetexta, the Curule Aediles also held the power to issue edicts (jus edicendi). These edicts often pertained to matters such as the regulation of the public markets, or what we might call "economic regulation".. Livy suggests, perhaps incorrectly, that both Curule as well as Plebeian Aediles were sacrosanct. Although the curule aediles always ranked higher than the plebeian, their functions gradually approximated and became practically identical. Within five days after the beginning of their terms, the four Aediles (two Plebeian, two Curule) were required to determine, by lot or by agreement among themselves, what parts of the city each should hold jurisdiction over.
There was a distinction between the two sets of Aediles when it came to public festivals. Some festivals were Plebeian in nature, and thus were under the superintendence of Plebeian Aediles. Other festivals were supervised exclusively by the Curule Aediles, and it was often with these festivals tbat the Aediles would spend lavishly. This was often done so as to secure the support of voters in future elections. Because Aediles were not reimbursed for any of their public expenditures, most individuals who sought the office were independently wealthy. Since this office was a stepping stone to higher office and the senate, it helped to ensure that only wealthy individuals (mostly landowners) would win election to high office. These extravagant expenditures began shortly after the end of Second Punic War, and increased as the spoils returned from Rome's new eastern conquests. Even the decadence of the emperors rarely surpassed that of the Aediles under the republic, as could have been seen during Julius Caesar's Aedileship.
Plebeian Aediles were elected by the Plebeian Council (popular assembly), usually while under the presidency of a Plebeian Tribune. Curule Aediles were elected by the Tribal Assembly, usually while under the presidency of a Roman Consul. Since the Plebeian Aediles were elected by the Plebeians (commoners), rather than by all of the People of Rome (Plebeians as well as members of the Patrician aristocracy), they were not technicaly magistrates. Before the passage of the lex annalis, individuals could run for the Aedileship by the time they turned twenty-seven. After the passage of this law in 180 BC, a higher age was set, probably thirty-five. By the first century BC, Aediles were elected in July, and took office on the first day in January.
Cicero (Legg. iii. 3, 7) divides these functions under three heads:
(1) Care of the city: the repair and preservation of temples, sewers and aqueducts; street cleansing and paving; regulations regarding traffic, dangerous animals and dilapidated buildings; precautions against fire; superintendence of baths and taverns; enforcement of sumptuary laws; punishment of gamblers and usurers; the care of public morals generally, including the prevention of foreign superstitions. They also punished those who had too large a share of the ager publicus, or kept too many cattle on the state pastures.
(2) Care of provisions: investigation of the quality of the articles supplied and the correctness of weights and measures; the purchase of corn for disposal at a low price in case of necessity.
(3) Care of the games: superintendence and organization of the public games, as well as of those given by themselves and private individuals (e.g. at funerals) at their own expense. Ambitious persons often spent enormous sums in this manner to win the popular favor with a view to official advancement.
In 44 BC Julius Caesar added two plebeian aediles, called Cereales, whose special duty was the care of the cereal (corn) supply. Under Augustus the office lost much of its importance, its juidical functions and the care of the games being transferred to the praetor, while its city responsibilities were limited by the appointment of a praefectus urbi. Augustus took for himself its powers over various religious duties. By stripping it of its powers over temples, Augustus effectively destroyed the office, by taking from it its original function. After this point, few people were willing to hold such a powerless office, and Augustus was even known to compel individuals into holding the office. Augustus accomplished this by randomly selecting former tribunes and quaestors for the office. Future emperors would continue to dilute the power of the office by transfering its powers to newly created offices. However, the office did retain some powers over licentiousness and disorder, in particular over the baths and brothels, as well as the registration of prostitutes. In the 3rd century AD it disappeared altogether.
Under the empire, Roman colonies and cities often had officials with powers similar to those of the republican aediles, although their powers widely varied. It seems as though they were usually chosen annually. Today in Portugal the county mayor can still be referred to as 'edil' (e.g. 'O edil de Coimbra', meaning 'the mayor of Coimbra').