Catholicism was started as a result of Jesus of Nazareth, a Jewish man whom Christians believe is the Son of God, a Christian belief known as the Trinity (Father, Son, and Holy Spirit). Catholics believe Jesus to be a descendant of David, a Jewish king from a long time ago. Jesus was crucified by the Romans in the year 33 AD. Catholics believe Jesus rose from the dead, and spoke to his followers, called the twelve Apostles. They also believe that Jesus rose into Heaven, and then sent the Holy Spirit to guide his followers at an event known as Pentecost.