Great teachers of the Church from at least the fourth century spoke of Mary as having remained a virgin throughout her life:
Athanasius (Alexandria, 293 - 373)
Epiphanius (Palestine, 315? - 403)
Jerome (Stridon, present day Slovenia, 345? - 419)
Augustine (Numidia, now Algeria, 354 - 430)
Cyril (Alexandria, 376 - 444)
Martin Luther(lutheran church) was one of the biggest defenders of this concept.
I thought Catholics weren't particularly fond of Martin Luther. In fact, I've seen him condemned as antisemetic right here on FR. Tell me, are you standing against the anti Luther rhetoric?