Did the early church accept lifelong, faithful concubinage?

In Bryan Litfin's book, [*Getting to Know the Church Fathers*](https://books.google.com/books?id=9RdGDAAAQBAJ) , I was surprised to read the following about concubinage in the early church, in the context of Augustine's life before conversion: > In Roman society, the practice of concubinage was widely accepted. Even the Christian church was prepared to accommodate it as a kind of common law marriage so long as there was lifelong fidelity. ((https://books.google.com/books?id=9RdGDAAAQBAJ&printsec=frontcover#v=onepage&q=common%20law%20marriage&f=false)) In Augustine's case, he had no intention of lifelong fidelity, so the point is rather moot. But in many places around the world, both historically and currently, government restrictions make it difficult or impossible for some men and women to be officially "married." My personal response might be to disregard the government's restrictions and consider a man and woman publicly committed to faithful monogamy as married, and not fornicating, particularly if they have a "church wedding." But in the Dominican Republic, at least, where I periodically do some ministry, the church I work with insists that those living together while not officially (legally) married are committing adultery, despite the legal barriers preventing some from marrying.1 All that to say, this isn't idle curiosity. **Did the early church "accommodate" faithful concubinage, as Litfin says? In what sense – was it in the musings of a single church father, or set down at an ecumenical council? And if so, under what circumstances would it be allowed?** ---- 1. For more on these barriers, see [this documentary](https://www.youtube.com/watch?v=DAqGuj8AT1U) or [its trailer](https://www.youtube.com/watch?v=WDCidZGov1M) .