16th pope Callistus 1 = Emperor Caracalla (Bassianus)?
Dates match: Callistus 1 ruled 217/218-222/223. Mentioned by Tertullian about 199? Caracalla reigned (197/198-209-)211-212-217. Both dates coincide at (198/199? &) 217.
Names match: Pope Callistus: The 16th pope's name Callistus/Callixtus/Calixtus. Emperor Caracalla: The emperors name is Caracalla from 'caracallus' "Gallic hooded tunic/cloak/garment". Both names Callistus & Caracalla are vaguely similar. Both are similarish Ca... names. Both contain Call-/-call.
Both are in Rome.
Callistus: Zephyrinus made him coemeritium. Caracalla: Co-emperor with Severus.
Callistus: opposed by antipope Hippolytus. Caracalla: Heliogabalus his illegitimate son.
Both pontiffex maximus: Callistus is bishop / "pope" / "pontiffex maximus" / "supreme pontiff" (Annuario Pontificio, Liber Pontificalis). Tertullian in ca 220 mentions Callixtus or Agrippinus of Carthage as pontiffex maximus. Caracalla was pontiffex maximus (the emperors from Augustus to Gratian/Theodosius were pontiffex maximus). [The argument that the titles pontiffex maximus and pope were not used by/for bishops of Rome until later (mid-5th & mid-6th centuries) and so is an anachronism is not necessarily valid because bishop/pope/pontiff are still related/similar.]
Pope Callistus: "The declaration of Carpophorus that Callistus was no Christian...." "The orthodoxy of Callistus is challenged by both Hippolytus and Tertullian...." "Hippolytus, however, regards Callistus as a heretic." Emperor Caracalla: not Christian.
Callistus like other early popes & sts is shown with a halo/aura. Caracalla shown with laureate head.
Callistus: Built an oratory (claimed by popinarii tavern-keepers). Built a church/basilica. Patron of the titulus of Basilica of St Maria. Caracalla: Forced senate to construct "palaces, theaters, and places of entertainment". Commissioned building of public bath(-house)s (which included libararies etc).
With both Callistus & Caracalla the popes & emperors before & after also match all in order. 1 Peter (Nero) = Nero (Peter) 2 Linus = Vespasian 3 Cletus = Titus 4 Clement 1 = Domitian (Clemens) 5 Evaristus = Nerva 6 Alexander 1 = Trajan (Alexander) 7 Sixtus 1 = Trajan? or Hadrian? 8 Telesphorus = Hadrian? 9 Hyginus (Graecvs) = Hadrianus (Graeculus) 10 Pius 1 = Antoninus Pius 11 Anicetus = 12 Soter = 13 Eleutherius = 14 Victor = Severus? (15a antipope Natalius = ?) 15 Zephyrinus/Zepheniah = Septimus Severus 16 Callixtus = Caracalla 16-19 antipope Hippolytus = Heliogabalus etc. See each separate pope & emperor chapter for matches details.
Callistus: Consigned to the pistrinum handmill. Caracalla: "... and even grinding his own flour with them."
Callistus: Connected with Elagabalus/Heliogabalus (Baal/El worship). "Antipope" Hippolytus was contemporary with him & was after him. Caracalla: His father/mother connected with Elagabalus/Heligobalus. Heliogabalus was illegitimate son of Caracalla. Heliogabalus/Elagabalus was emperor not long after him. (Antipope Hippolytus matches emperor Heliogabalus/Elagabalus.)
Callistus: "Martyr". Cemetary/catacombs of Callistus. Caracalla: [Murdered/assasinated by a soldier.] Notorius & unpleasant for massacres & Persecutions he authorized & instigated.
Callistus: "Further there is extant an inscription of a Carpophorus, a freedman of M. Aurelius...." Caracalla: Created a connection with Marcus Aurelius.
Callistus: Prefect Alexander (just after his death). Caracalla: Alexander the Great mimic/mania.
Callistus: Connected with "pope" "Victor". Caracalla: Connected with military? His father was Severus (who might match Pope Victor 1, see that chapter).
Callistus: "...was put in charge of collected funds by his master Carpophorus...." "His master entrusted large sums of money to Callistus, with which he started a bank in which brethren and widows lodged money, all of which Callistus lost." "...he tried to borrow money or collect debts from some Jews." "...it is clear that he asked the Jewish money-lenders to repay what they owed him...." "If Pope Victor granted Callistus a monthly pension...." ("He obtained great influence over the ignorant, illiterate, and grasping Zephyrinus by bribes.") Caracalla: "New and heavy taxes were levied against the bulk of the population, with additional fees and confiscations targeted at the wealthiest families." "to increase state revenue", "raising tax revenue", "expanding the Roman tax base". ("About the time of his accession he ordered the Roman currency devalued, the silver purity of the denarius was decreased from 56.5% to 51.5%...." / "debasement of the currency".)
Callistus: Was a "runaway slave (now free by Roman law from his master...." "... in a famous edict he granted Communion after due penance to those who had committed adultery and fornication. .... ... The edict was an order to the whole Church.... .... ... and the pope in decreeing a relaxation was regarded as enacting a new law. .... ...Again Callistus allowed the lower clergy to marry, and permitted noble ladies to marry low persons and slaves, which by the Roman law was forbidden...." "...he started to admit into the church converts from sects or schisms who had not done penance. ...and established the practice of absolution of all sins.... Hippolytus found Callixtus's policy of extending forgiveness of sins to cover sexual transgressions shockingly lax and denounced him for allowing believers to regularize liaisons with their own slaves by recognizing them as valid marriages. " "Further there is extant an inscription of a Carpophorus, a freedman of M. Aurelius...." Caracalla: "the Constitutio Antoniniana (also called the Edict of Caracalla or the Antonine Constitution), granting Roman citizenship to all freemen throughout the Roman Empire...." "The Constitutio Antoniniana (Latin: "Constitution [or Edict] of Antoninus") (also called Edict of Caracalla or Antonine Constitution) was an edict issued in 212 by Caracalla which declared that all free men in the Roman Empire were to be given full Roman citizenship and all free women in the Empire were given the same rights as Roman women. Before 212, for the most part only inhabitants of Italia held full Roman citizenship. .... The effect of this was to remove the distinction that citizenship had held since the foundation of Rome and as such the act had a profound effect upon the fabric of Roman society." "He forgot even the proper dignity of his rank...."
No contemporary proof of existence of a bishop Callistus outside of church writings. Certain details only "likely to be historical". "Possible" he was martyred. "Many popes in the first three centuries of the Christian era are obscure figures". Though Callistus is mentioned by Hippolytus (between 217 & 235), Tertullian (199? or ca 220), enemies writings (ca 222), and Julius Africanus (ca 223). But this may just mean that they first started the popes/emperors correspondences as early as those writers. Church writings should be treated with wariness as to their honesty. History shows that some people can lie, esp when they have a religious agenda. The Acts of Callistus are spurious. There are the catacombs of Callixtus (mid 2nd century or beginning of 3rd century?) But do they have any contemporary inscription with name of bishop Callistus?