Traditionally, two were simultaneously appointed for a year-long term, so that the executive power of the state was not vested in a single individual, as it had been under the kings.
Many such lists have survived, either in the form of monumental inscriptions, conventionally referred to as fasti, or indirectly through the ancient historians, who had access to linen rolls recording the names of magistrates.
Although these lists account for the entire period of the Republic, and most of Imperial times, there are discrepancies due to gaps and disagreements between different sources.
Others may represent later attempts to edit the lists in order to explain deficiencies in the record, to reconcile conflicting traditions, or to ascribe particular actions or events to the time of a particular individual.
According to tradition, a second college of decemvirs was appointed for the next year, and these continued in office illegally into 449, until they were overthrown in a popular revolt, and the consulship was reinstated.
[6][7] Among the disputes which the decemvirs failed to resolve was the relationship between the patricians, Rome's hereditary aristocracy, and the plebeians, or common citizens.
[2][8] According to Livy, this compromise held until 376 BC, when two of the tribunes of the plebs, Gaius Licinius Calvus Stolo and Lucius Sextius Lateranus, blocked the election of any magistrates for the following year, unless the senate would agree to place a law before the people opening the consulship to the plebeians, and effecting other important reforms.
[2][8][9] Other accounts of this event are inconsistent, and current scholarly opinion is that the duration of the period without magistrates may have been exaggerated, or even invented to fill a gap in the record; nevertheless Roman tradition unanimously holds that Licinius and Sextius were able to open the consulship to the plebeians.
[1][2] As the office lost much of its executive authority, and the number of consuls appointed for short and often irregular periods increased, surviving lists from Imperial times are often incomplete, and have been reconstructed from many sources, not always with much certainty.
The last consuls appointed represented only the Eastern Empire, until finally the title became the sole province of the Emperor, who might or might not assume it upon taking office.
[16][17] The surviving sources for the order of the consuls in the early Republic show some measure of conflict in just under half of the cases.
[19][20][21] Drummond disagrees: he argues that Livy himself switches the correct order at times for literary purposes, and that discrepant entries in the sources are most likely simply the result of negligence.
[214] The late antique practice of granting honorary consulships eventually evolved into the Byzantine court dignity of hypatos (the Greek translation of the Latin consul), which survived until the 12th century.