The second pope of the Catholic Church was Pope Linus. He succeeded Saint Peter as the Bishop of Rome and served as pope roughly from AD 67 to AD 76 or 80, according to various historical sources

. Key points about Pope Linus include:

• He was likely born in Volterra, Tuscany, Italy

• Linus was a follower and close companion of Saint Peter and was consecrated by him as a bishop

• He played a significant role in organizing the early Church, appointing bishops, and spreading Christianity during a time of persecution under Emperor Nero

• Linus is one of the few early popes mentioned by name in the New Testament, along with Peter and Clement

• His feast day is celebrated on September 23

• Some historical debates exist about whether Linus or Anacletus (Cletus) was the second pope, but the Catholic Church officially recognizes Linus as the second pope after Peter

In summary, Pope Linus is traditionally regarded as the second pope, following Saint Peter, and was instrumental in establishing the early Church's structure and leadership during a challenging period for Christians.