Peter and Paul became an inseparable pair in later church art and tradition. Traditionally, Peter is depicted with grey hair and short beard; Paul has balding brown hair and a full beard. In this illumination from a late 17th-century hymnbook, Peter (left) holds the key to the kingdom; Paul (right) carries a book and the sword with which he was martyred.
By the late second century, Peter and Paul were hailed as cofounders of the church in Rome. In the New Testament, however, they appear to meet only three times: twice when Paul goes to Jerusalem to meet with church leaders and once in Antioch (Galatians 1:18, 2:2, 11).