According to Vishnu Puran, Lord Vishnu created Lord Shiva and according to Shiva Purana it's vice versa. In Devi Bhagavata Purana, Adi Shakti created both Lord Vishnu and Lord Shiva. So, what is the actual truth?
According to Srimad Bhagavatam written by A.C Bhaktivedanta Srila Prabhupada, Lord Brahma came from navel of supreme personality of God head Sri Maha Vishnu .
Lord brahma created the four kumaraya & told them to take responsibility of the procreation of the universe. They did not obey him. So Lord Brahma Ji got angry & from his eye brows came a baby crying. That is Lord Rudra. ( Lord Shiva )
He is the Lord of destruction. Lord Vishnu is the maintainer.