Jakob Ammann was a Swiss Mennonite bishop who, in the early 1690s, concluded that his fellow ministers had grown lax in applying the ban, the practice of excommunicating and then shunning members who violated their baptismal vows or church discipline. Ammann argued for Streng Meidung, strict shunning, meaning that even a spouse or close relative under the ban should be avoided in ordinary social life, including at the table, until repentance restored fellowship. He also pressed for twice yearly foot washing as part of communion and for plainer, more uniform dress than many Swiss Mennonite congregations then practiced.
When the wider ministerial body declined to adopt his standard, Ammann and his followers separated in 1693, and the division, despite several attempts at reconciliation in the years immediately following, proved permanent. The group that formed around Ammann took his name, becoming the Amish, while the majority who did not follow him continued as Mennonites. The split therefore did not turn on any disagreement over core Anabaptist doctrine, believer's baptism, nonresistance and separation from the world were common ground on both sides, but specifically on how visibly and how strictly that shared doctrine of separation should be enforced within the community itself, a question the Ordnung exists to keep answering generation after generation.