The following "timeline" is divided into periods that make sense from an internal Christian perspective.  For a comparative timeline (between Jews, Christians, and Muslims) click here

significant terms are in small caps/bold

I.  THE MINISTRY OF JESUS (circa 30 CE)
Continuing for anywhere from one to three years, a Galilean Jew named Jesus preached a message of redemption and atonement (firmly in the context of other Jewish religious revivals), gathered followers in his native Galilee, preached in Jerusalem and was executed (around 30 CE).  At some point after his death by public crucifixion, his disciples came to believe that a) he rose bodily from the dead (resurrection) and b) he was the messiah (anointed one) promised by God for human salvation.  Our only sources for the life and message of Jesus are the writings of the new testament.

II.  THE APOSTOLIC PERIOD (circa 30-60 CE)
Both original disciples of Jesus and those who came to believe his messiahship after his crucifixion (such as Paul) began to spread his message around Jerusalem and the Greek-speaking eastern part of the Roman empire.  Paul's letters suggest an original plurality and diversity of the beliefs and practices of these early communities.  Most of our sources suggest that the movement was largely apocalyptic at this point, anticipating an imminent end to the present world order.  By the 60s, there were small communities of followers all the way from Jerusalem to the city of Rome.

III.  "CHURCH OF THE MARTYRS" (circa 100-300 CE)
Some time in the second century, factions of the followers of Jesus deliberately broke from their Jewish origins. At this point we can beginning considering a new, distinct religion, "Christianity."  Christian communities became prominent enough to draw the disapproving attention of the Roman officials:  Nero blamed the Christians for the great fire of Rome, in the 60s CE; a governor in Bithynia (modern Turkey) executed individuals simply for the crime of being Christian, considered a subversive and potentially seditious movement.

persecution of Christians was neither systematic nor widespread until two brief attempts in the third century. The undercurrent of suspicion against Christians was internalized by many Christian communities who began to conceive of themselves as a holy church of "martyrs," facing off on the side of God against the evil and corrupt Roman empire.

During this period, the original multiplicity and diversity of Christian movements in matters of belief and practice began to harden into a discourse of heresy and orthodoxy.

IV.  "THE CHURCH TRIUMPHANT" (circa 300-600 CE)
In the year 313 CE the new emperor Constantine (later known as "the great") legalized Christianity, and began to give money and benefits to Christian churches around the empire.  Following Constantine, all of the emperors of the Roman empire were Christian (with one exception:  Julian, who reigned from 361-363 CE), and the next centuries witnessed an increasing fusion between the interests of the Roman empire and the Christian church.  By the fifth century CE, Christianity was considered the "official" religion of the empire.  During this time, most apocalyptic expectations began to fade from mainstream Christianity.

This merging of "church" and "state" continued as the Roman empire disintegrated:  by 600 CE, most of the western half of the Roman empire was in the hands of non-Roman "barbarians," all of whom (eventually) converted to mainstream (Catholic) Christianity.  In the east, the Roman empire continued in various forms throughout the middle ages (known to historians as the Byzantine empire).

During this period, a canon of Christian Scriptures (old and new testaments) came to be regularized, as did clerical offices (priest, bishop) and non-clerical forms of religious vocation (monks, nuns, hermits).  Theological sophistication developed complex notions of religious rituals, definitions of divinity, and modes of Christian salvation and damnation.

V.  MEDIEVAL CHRISTENDOM (circa 600-1500 CE)
The rise of "Christendom" (circa 600-1000 CE)
Christians in western Europe simultaneous created distinct nation-state kingdoms, such as France, England, Spain, and so forth, while also understanding a theoretical unity:  all Christians under the spiritual leadership of the bishop of Rome (the pope). 

Political rulers and church leaders consolidated their power during this period.  From around 600 onward, the bishop of Rome (the pope) solidified his spiritual and earthly authority, often in tandem with political rulers (such as Charlemagne, who crafted a Roman-style empire in western and central Europe, and his later self-styled successors, the "holy Roman emperors," who formed politico-religious treaties with the pope).

The pope often sent priests and monks as missionaries to neighboring, non-Christian states in an attempt to convert them and increase the scope of the Christian world.  The Russians, Scandinavians, various central and northern European ethnic groups were converted in the centuries leading up to the millennium (1000 CE). 

Christendom challenged, and affirmed (circa 1000-1300 CE)
Two events challenged, and affirmed, this notion of a unified, singular European Christendom:

1. The rise of Islam, which quickly gained a foothold in Europe in the eighth century, and remained solidly entrenched in Spain (as well as Africa and the near east) throughout this period.
2.  Increasing tension with the eastern churches (who styled themselves orthodox instead of catholic), who refused to submit to the primacy of the bishop of Rome.  By 1100, a rift had formed between the eastern Orthodox churches and the Roman Catholic church.

The awareness of these "others" on the borders of Christendom (as well as a prominent population of "others" within Europe, the Jews) led to various intellectual, cultural, and political attempts to bolster the unity and strength of European Christian identity.

Theological sophistication incorporated philosophical ideas to illuminate increasingly complex notions of sin, atonement, salvation, and theology (definitions of god) often in the new scholasticism in the catholic university (a notion adopted from Islam).  Spiritual innovations were often undertaken by powerful popes, and new monastic orders.

During this period both internal and external attempts to bolster catholic unity were launched:  the reconquista, an attempt to rechristianize the Iberian peninsula (eventually successful in 1492 CE); the inquisition, an attempt to root out heretics; and the crusades, a military-religious effort to seize the sites of biblical history from "the unfaithful" (i.e., the Muslims).

In the Byzantine east, conflict and contact with Islamic thinkers hardened the political and religious boundaries of the old Roman empire, and led to particular religious conflicts and developments, such as the debate of the sanctity of images (iconoclasm). by the end of this period, the Byzantine empire had all but vanished under the military expansion of the Muslims (ottoman Turks).
 

VI.  REFORMATION/COUNTER-REFORMATION (circa 1500-1700 CE)
Protestant origins and Catholic response (1500-1600 CE)
By the end of the middle ages, some Christians resisted the hardened control of the pope and the theological rigidity of scholastic theology.  From the fourteenth century on, attempts at reformation of the catholic church resulted in the splintering of unified European Catholicism into distinct forms of Christianity.

Martin Luther, John Calvin, Ulrich Zwingli, and other reformers emphasized the centrality of scripture, faith (as opposed to ritual works), and individual salvation and damnation.  Their movements developed into various branches of Protestantism (a collective term for Lutheran evangelical, Calvinist/reformed, and radical reforming Christianities) with footholds in particular geographic locations.

The catholic church also launched a reformation, emphasizing renewed spirituality and mysticism, and affirming the authority and power of the papacy.

Technological and political innovation also changed Christian perspective:  the printing press allowed for the circulation of Bibles and religious tracts, and increased literacy; and early colonization of the "new world" (North America and the Pacific East) increased contacts with non-Christian populations.

Wars of religion (1600-1700 CE)
Religious conflict in Europe erupted into open warfare: economic revolts, rival political leaders with backing from different Catholic and Protestant groups.  By the 1700s CE uneasy peace had developed under the motto cuius regio, eius religio ("to each region its own religion"), cementing the religious fragmentation of Europe. Individual nations developed particular religious character: protestant Germany, catholic France, Anglican England, and so forth.

VII.  MODERN AND GLOBAL CHRISTIANITIES (circa 1700 CE-present)
The age of empire (1700-1900 CE)
The "age of exploration" evolved into the age of imperialism: Christian missionaries often traveled with imperial functionaries (from France, England, Holland, Spain) in an effort to spread Christianity to "natives." the diversity and fractiousness of European Christianity spread across the globe.  One result was the creation of a deliberately multireligious political nation in North America (the united states), which attempted to craft an uneasy balance between freedom of religion and its European Christian origins.

Massive empires spreading from western Europe, especially in the eastern hemisphere, led to the weakening of local states and cultures under European rule and influence (India, turkey, Egypt, Africa) .  Religious and political forms of resistance emerged towards the end of the imperial period, emphasizing local religious and political autonomy.  The first world war (1914-1919) resulted in a new understanding of the link between culture, religion, and nationalism as the old empires disintegrated..

Technological and philosophical advancements also challenged Christian world-views:  the industrial revolution and the rise of philosophical rationalism both emphasized human progress over divine providence, weakening the hold of organized religion over daily life.  Religious revivals and new Christian movements (Methodists, Quakers, Mormons, Baptists) emerged in response to this new secularization.

Modernity and globalism (1900s CE-present)
Continuing multiplicity and diversity of Christianity, linked to the emergence of cultural and political entities independent of European control, created a complex set of concerns for global Christianities:

Tension between Christian and native cultures has resulted into the (eventual) modernization of religious traditions, such as the second Vatican council (1962-65 CE) that allowed for recitation of ritual services in local languages and the incorporation of local customs.  Other forms of Christianity likewise struggle with the tension between Christian tradition and recognizing the value of non-European custom.

In the wake of World War II, Christians (in Europe and elsewhere) also started making efforts to connect better with other religious faith traditions, aware of the role played by religious prejudice in the violent wars of the 20th century CE.  Movements emphasizing ecumenism (unity between different branches of Christianity) and interfaith (dialogue between Christians and non-Christians) have emerged.

Christian identity, however, continues to serve as a flashpoint for political and cultural conflict, and modernized nation-states struggle with values of unifying traditional identities (religious, cultural) and the global values of diversity and multiculturalism.