Gaccha

A gaccha typically begins with a single acharya whose disciples come to see existing practice, whether around temple ritual, dress, calendar reckoning or monastic residence, as having grown lax or as having drifted from what they take to be the tradition's original discipline. The disciples of that reforming teacher then organise around his authority and his rules, and if the group endures across further generations of ordained successors it becomes a named gaccha in its own right, carrying his teaching lineage forward under rules that later members are expected to keep even after the founder's death.

This is a continuing process rather than a closed medieval event: a successful gaccha can itself divide again long after its founding, most often into sub lineages, called samudaya, that form around different senior acharyas within the same gaccha name rather than breaking away to found an entirely new one, so that a single historic gaccha can carry several living leaderships side by side today, distinguished by which acharya's teaching succession a particular monastic or temple follows rather than by any difference visible to an outsider. Disputes over the correct date for major festivals, a matter of calendar reckoning rather than doctrine, have been a recurring cause of these later divisions, since Jain monastics follow a lunar calendar that occasionally requires a decision about how to handle an intercalary month, and different lineages have not always agreed on the same solution.