The name Marcus, and its shortened form, Mark, come from Latin. Marcus was one of the most popular names in Roman history. Scholars believe the name is derived from the deity Mars, the Roman god of war. It may also have been a popular name given to children born during the month of Martius (modern March), which itself is named after the god Mars. One of the most famous men named Marcus in antiquity was Marcus Aurelius, a Stoic philosopher who served as Roman Emperor from 161 to 180 CE. In the Bible, there is a John Mark (Ἰωάννης Μᾶρκος, or Iōannēs Markos) mentioned in Acts 12:12 and 25, who ended up accompanying Barnabas on a mission to Cyprus. Scholars and historians are unsure if this is the same Mark as "Mark the cousin of Barnabas" mentioned in Philemon 24, Colossians 4:10, and 2 Timothy 4:11. Another Mark is mentioned in 1 Peter 5:13, whom the author refers to as his "son." And of course, there is the author of the Gospel of Mark, who may be one of the above or someone completely different. This is one of the problems with a name as popular as Marcus in antiquity.