Spencer is Courtney's (Sonny's sister) child with Nikolas Cassadine. (Original birth name: John Michael Jacks). He is Sonny's nephew and Mike's grandson. Courtney died shortly after childbirth due to complications with the virus outbreak. Before she died, she named her baby, thinking Jax was the father. "John after your father and Michael after mine. John Michael Jacks." Nikolas didn't find out he was the father until the baby's baptism, when Robin Scorpio confronted Jax and Carly, who were raising the baby together. Nikolas started raising Spencer at Wyndemere. In June 2011 Spencer moved to Zurich, Switzerland with his father. Nikolas returns to Port Charles in 2013. Sonny starts to mentor his nephew with some boxing lessons and they become close.