The medieval story is neat: the apostles, before scattering to preach, composed a creed together, each contributing one clause, so that twelve articles carry twelve names. It is a good story and it is not true. No ancient writer knows it, the earliest versions of the tale disagree about which apostle said what, and the text itself grew slowly in one region rather than arriving whole from Jerusalem.
The moment the legend was tested is worth recording. At the Council of Florence in the fifteenth century, Latin and Greek delegates met to seek reunion, and the Latins appealed to the creed of the apostles. The Greeks replied that they possessed no such thing. The Eastern churches had never used it, never had, and knew nothing of the story of its composition. A creed the apostles wrote could hardly be unknown to half the church they founded.
What is true is more interesting than the legend. The creed descends from the baptismal interrogation of Rome, which is genuinely very old, and it reached the wording used today in Gaul, from where Charlemagne's reform of the liturgy carried it across the West. Its content is apostolic in the sense that it says what the earliest preaching said. Its manufacture is not, and treating the two claims as one is how a legend gets defended long after the text that supports it has been read.