Sourced guide
The shortest documented chain from Jesus to Irenaeus
The tightest documented route in the dataset is Jesus -> John the Apostle -> Polycarp of Smyrna -> Irenaeus of Lyons.
Chain in the data
Why this chain matters
Irenaeus is one of the first major Christian theologians outside the New Testament. His link to Polycarp matters because Polycarp is remembered as a hearer of John the Apostle.
That makes Irenaeus unusually close to apostolic memory: not in the same generation as the apostles, but close enough that his argument from public apostolic teaching has historical weight.
What documented means here
Documented does not mean modern video-level certainty. It means the relationship is directly attested in the ancient source base used by this dataset.
For Polycarp and Irenaeus, the key evidence is Irenaeus's own memory of hearing Polycarp and his report that Polycarp had known John and others who had seen the Lord.
Relevant relationships
Forward edge into the next era. Irenaeus in his Letter to Florinus describes hearing Polycarp preach in his youth at Smyrna.
Irenaeus, who personally heard Polycarp in his youth, states in Adv. Haer. 3.3.4 and his Letter to Florinus (Eus. HE 5.20) that Polycarp was instructed by John and 'others who had seen the Lord'. This is a near-contemporary chain (Irenaeus -> Polycarp -> John), so 'documented'.
Irenaeus describes in his Letter to Florinus hearing Polycarp preach in his youth in Smyrna and remembering his testimony about John the Apostle. This is direct first-person testimony.