Which is to say, the Catholic Church.
The thing to keep in mind, here, is that the diocesan (Church) structure tended to assume responsibility for civil well-being as the secular diocesan (civic) order decayed. The monasteries did as well: they provided for order, stability, and the re-establishment of the rule of law in the aftermath of barbarian invasion and widespread disorder.
To separate "diocesan" and "monastic" can be misleading. True, the monasteries often were founded in separately from any local diocesan structure, but these were all Catholic institutions. They held Catholic and Apostolic convictions, they were Catholic in faith and morals, they maintained the Catholic Scriptures (Bible) and the Catholic liturgical and sacramental life, they were in communion with the Bishop of Rome and the rest of the Church.
Thus, through the vicissitudes of history, the Bride of Christ continued on her pilgrim way. From Pentecost to today.
“Thus, through the vicissitudes of history, the Bride of Christ continued on her pilgrim way. From Pentecost to today.”
I can certainly agree with the above statement. The resilience of the Christian faith is confirmed by survival within a bureaucratic structure committed to worldly advancement during this period.