Complex sentence: Although it adopted the symbolic name ("seiz breur " means"seven brothers " in Breton), in practice it was made up of at maximum fifty members, under the name"Unvaniezh Seiz Breur" (Union of the seven brothers).
Split into simpler sentences: Although it adopted the symbolic name "seiz breur", meaning "seven brothers" in Breton, this did not refer to the number of members. At its height it had fifty members united as the "Unvaniezh Seiz Breur" (Union of the seven brothers).