[TheFreim]

> It chops and changes with no explanation.

The site provides the relevant information. In the "Story of the Basilica" the first section is "The Life of St. Peter" and it tells you why Simon came to be called Peter.

https://virtual.basilicasanpietro.va/en/st-peter-history

[lostlogin]

The name changes before mentioning that he is renamed by Jesus. But yes, it does explain later on. I’d skipped to Wikipedia by then.