The Edict of Milan (AD 313) ends Roman persecution and grants Christianity legal status. Twelve years later, Constantine convenes the Council of Nicaea (AD 325) and presides over its theological decisions. The Hebraic roots are formally severed: Pesach is replaced with Easter, calculated from a pagan equinox formula. The Sabbath is shifted to Sunday by imperial edict. Torah-keeping is recast as "Judaizing" — a punishable heresy. The institutional church is born — fused with empire, hostile to its Jewish foundation.

Augustine systematizes the doctrines that harden into Catholic orthodoxy. Replacement theology — the church as "the new Israel" — is given philosophical scaffolding. He defends infant baptism on the basis of inherited original sin, codifies amillennial eschatology (later picked up by Rome and the Reformers), articulates the doctrine of predestination Calvin will inherit, and authors "just war" theory. In his framework, Israel is permanently displaced; Torah becomes obsolete. His shadow falls across every Western branch that follows — Catholic, Lutheran, Reformed, evangelical.

Centuries of accumulated tradition rupture into mutual excommunication. Papal claims of universal authority, the filioque clause inserted into the Nicene Creed without ecumenical consent, and ritual disagreements about leavened versus unleavened bread split the Western and Eastern churches into Roman Catholic and Eastern Orthodox. Both retain replacement theology, infant baptism, Sunday worship, the veneration of icons, and the Constantinian severance from Hebraic roots.

Luther's 95 Theses challenge papal indulgences and launch Sola Scriptura. He breaks Rome's ecclesial authority — but keeps infant baptism, replacement theology, the institutional structure, and Sunday worship. Late in life he writes "On the Jews and Their Lies" (1543), advocating the burning of synagogues, the destruction of Jewish homes, and the seizure of their books — language that would be quoted approvingly by the Third Reich four centuries later. The Reformation reshuffles Catholic theology; it does not return to the Hebraic trunk.

A radical reformation — believers' baptism by personal confession, separation of church and state, refusal of military oaths, communal living. Persecuted by Catholics, Lutherans, and Reformed alike — Manz is drowned by the Zurich council, thousands are executed across Europe. Theologically a step closer to the trunk on practice, but still bound to Reformation framework, replacement theology, and Sunday worship. Spawns Mennonites, Hutterites, Amish, and the broader free-church movement.

A political break, not a theological one. Rome refuses Henry's request to annul his marriage to Catherine of Aragon; he passes the Act of Supremacy declaring himself Supreme Head of the Church of England. The doctrine, liturgy, episcopate, and sacraments remain largely Catholic. The monarch — not the Pope — becomes head of the church. Anglicanism becomes the established religion of the English crown, exported with empire to America, Africa, India, and Australia. Spawns Episcopalian and global Anglican Communion.

Calvin systematizes Augustinian theology into the Five Points (TULIP): total depravity, unconditional election, limited atonement, irresistible grace, perseverance of the saints. God is said to elect some to eternal salvation and others to eternal damnation before creation — a doctrine of double predestination. Sabbath is dismissed as "ceremonial" and replaced with a Christian-Sunday observance. Geneva becomes a theocracy under his oversight; Servetus is burned at the stake for denying the Trinity. Calvinism shapes Puritanism, Presbyterianism, the Dutch Reformed tradition, and most modern evangelical theology.

Believers' baptism by full immersion, congregational governance, separation of church and state. Rejects infant baptism but retains Sunday worship and replacement theology. Spawns Southern Baptist (the largest Protestant body in America), American Baptist, Reformed Baptist, Independent Fundamentalist Baptist, and dozens of smaller subdivisions. Doctrinally varied — Calvinist, Arminian, dispensationalist — united mainly by anti-paedobaptism.

A revival movement within Anglicanism that becomes its own denomination after Wesley's death. Holiness, sanctification, methodical devotion. Wesleyan-Arminian theology rejects Calvinist predestination in favor of universal atonement. Spawns Holiness churches, Wesleyan Methodist, Free Methodist, Nazarene, Salvation Army, and is the theological soil from which Pentecostalism later grows.

Joseph Smith claims new revelation — golden plates translated by seer stones into the Book of Mormon, additional living prophets, ongoing scripture (Doctrine and Covenants, Pearl of Great Price). A wholly distinct theology of God (an exalted man), of man (a potential god), and of salvation (degrees of glory, eternal marriage, baptism for the dead). Most theologians outside the LDS tradition — including evangelicals, Catholics, and Eastern Orthodox — classify it as a separate religion, not a Christian denomination.

Born from William Miller's failed prediction of Yeshua's return on October 22, 1844 — "the Great Disappointment." Ellen G. White becomes the movement's prophetess and produces voluminous extra-biblical writings still treated as authoritative. They restore seventh-day Sabbath observance — a partial return toward the trunk — yet are bound by White's prophetic authority and a unique "investigative judgment" doctrine that is found nowhere in Scripture but central to Adventist theology. Note: Seventh-Day Adventist (SDA) is not the same as Seventh-Day Baptists, an older Sabbath-keeping Protestant tradition founded in 1671, nor as the Russian Subbotniks of the 1700s. The names are similar; the histories are not. See Notes below.

Russell denies the deity of Yeshua, the personality of the Holy Spirit, and eternal punishment. The Watchtower Society produces its own translation — the New World Translation — that conforms to the movement's theology rather than the underlying Greek and Hebrew. A rolling history of failed end-time predictions: 1914, 1925, 1975. Members are forbidden blood transfusions, military service, holiday celebration, and continued association with former members. A separate theological universe.

The Azusa Street Revival in Los Angeles ignites the modern Pentecostal movement. Tongues, prophecy, divine healing, and Spirit baptism are taught as a "second blessing" subsequent to conversion. Branches into Assemblies of God, Foursquare, Church of God in Christ, Oneness Pentecostalism, and the global Pentecostal-Charismatic stream — now the largest single tradition within Protestantism, with an estimated 600 million adherents worldwide.

Pentecostal practice exported into Catholic, Anglican, Lutheran, and mainline Protestant streams. Tongues, prophetic words, healing services, contemporary worship. Reshapes evangelical Christianity globally and produces the modern "praise and worship" industry, complete with stage lighting, fog machines, and emotional-arc-driven service design.

"Just the Bible" as branding — but in practice, a fusion of evangelical Calvinism, charismatic worship, and seeker-sensitive marketing. Doctrine flattened to the lowest common denominator to maximize attendance. Pastors function as CEOs, services as productions, members as customers. Replacement theology, Sunday worship, and Constantine's calendar carried forward, now repackaged with stage lighting and Instagram. The largest growth segment of American Christianity.