The first two of these schisms, producing the Assyrian Church and the Coptic, are rooted in what is called the Nestorian heresy. Nestorius held that Christ was two persons in one, one human, one divine, while the Church asserted, at the Council of Ephesus (431) that Christ had two natures, human and divine, but only one person in which these two natures were present at once and simultaneously. The split-off of Coptic Christians came twenty years later, after the Council of Chalcedon (451) over a variant of the Nestorian heresy, monophysitism. It held that Christ was a single person with a single nature, both divine.
The third great division, which produced the Eastern Orthodox branch, was initiated by ideas of Photius (820-893), the patriarch of Constantinople. His assertion was that the Holy Spirit arose from the Father. The Church asserted, at the Fourth Council of Constantinople (869-870), that the Holy Spirit proceeds from the Father and the Son (Filioque, in the Latin of the Nicene Creed, thus this word became the name of the controversy). Photius also disapproved of Leo III’s crowning of Charlemagne as Holy Roman Emperor and openly criticized clerical celibacy. The Fourth Council set the stage for what is known as the Great Schism, the third. It took place in 1054 when the then leader of the Church in Constantinople, Michael Cerularius, shut down Latin churches in Constantinople; he was excommunicated by Leo IV, and the split became history.
The graphic, of course, also shows later separations and, in some cases, reunions of elements of split-off streams with the main stream, Catholicism.
Some will read this and smile, feeling superior. But, alas, in the realm where we are all sojourning, things get very messy—but, as Rumi, the poet, says, “the caravan keeps marching on.”