Note 11 at 1Co 15:5: This term "twelve" is actually describing the eleven apostles of Jesus (Lu 6:13-16). Judas had already hung himself (Mt 27:3-5). Matthias was chosen by the apostles to replace Judas (Ac 1:26), but this wasn't until after the ascension of Jesus. Therefore, at the time Paul was describing here, only eleven of the original twelve apostles remained.