Roman native Pope Julius had to deal with problems right out of the gate. The heresy of Arianism,which basically believed that God and Jesus were two separate beings,started to become a issue in the Eastern Churches. Pope Julius exerted his authority over Eastern Bishops that were trying to spread this new heresy,and he helped back up St.Athanasius of Alexandria who was defending the faith on the front lines of this heresy battle. Pope Julius should really be known as the man who officially declared December 25th as the day we celebrate the birth of our Lord. Nobody really knows when Jesus was born,but early Christians would celebrate this event in secret by piggy-backing onto a pagan sun god holiday that took place in late December/early January.Once Christianity was allowed,it was easier to co-opt this holiday with pagans and Jews rather than force a new holiday on non-Christians.The first official December 25th Christ’s Mass,(or X-Mas to you damned heathens), took place in 336 and Pope J stamped it into the books a few years later.