When Jesus stood before Pilate, He was asked, “Are you a king?” and from the conversation that followed Pilate the gentile and his gentile wife St. Claudia Procla saw that He was indeed a king.
The apostles had some understanding that Jesus, a son of David was a king by right but they were stuck in the idea that He would take a political stand against Rome and somehow bring all Israel back together. When Jesus went out to do His mission there was only Judea, the land of Judah and Benjamin with the Levite priesthood. Sometimes other tribes were noted such as Anna in the Temple who was from the tribe of Ashur. But in saving all Israel Jesus wasn’t going to pick out Israelites alone. He was calling all the nations, the gentiles too now, into the new Israel of the new Covenant. Israel was the first born son, the oldest brother of us all, but the gentiles were God’s children too.