H.R.H. Prince Robert Keoua Kalanikupuapaʻikalaninui Wilcox was the only son of H.R.H. Princess Theresa Owana Kaʻōhelelani Laʻanui Wilcox, and her husband, the Honorable Robert Kalanihiapo Wilcox.  He was named was after his father, Robert Wilcox and his middle name after his family lineage of Keōua Nui on his mother's side of Princess Theresa.

Prince Robert Keōua was to become the head of the royal house, unfortunately he died in 1934 at an early age of 41. His first child, H.R.H. Princess Helena Kalokuokamaile, the absolute primogeniture heir became the head of the royal house after Princess Theresa's death in 1944. Her daughter, H.R.H. Princess Owana Kaʻōhelelani Salazar succeeded her and became the head of the royal house in 1988.