The 1256 union that created the Augustinian friars gathered together several previously separate communities of Italian hermits under one rule and one governing structure, a deliberate consolidation distinct from the older, unrelated tradition of Augustinian Canons Regular, clergy who had followed Augustine's rule in a more settled, parish adjacent form for centuries before the friars existed at all. The friars' subsequent history was shaped decisively by a single member: Martin Luther entered an Augustinian monastery at Erfurt in 1505, was ordained within the order two years later, and carried the intense scrutiny of conscience his Augustinian formation encouraged into the crisis that produced the Ninety Five Theses and, eventually, the Protestant Reformation, an outcome no order founder could have anticipated but one permanently associated with the Augustinian name in a way true of no other medieval order.
Like the Franciscans, the Augustinians experienced their own internal division between stricter and more relaxed observance in the centuries after their founding, producing reformed congregations that argued, in familiar terms, that the order's original eremitical intensity had been diluted by its growth into settled, urban, mendicant life.