Sourced guide
Who taught Polycarp?
The important ancient claim is that Polycarp was instructed by John the Apostle and by others who had seen the Lord. Irenaeus, who heard Polycarp as a young man, is the key witness.
Chain in the data
The basic chain
The chain is Jesus -> John -> Polycarp. Polycarp then becomes the bridge to Irenaeus.
That is why Polycarp is one of the most important figures on the site even though only one short letter survives under his name.
Why Irenaeus is central
Irenaeus is not merely repeating a remote rumor. He describes remembering Polycarp's teaching from his own youth.
Because of that, this dataset marks the John and Polycarp connection as documented rather than merely traditional.
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.