Honolulu comes from Hawaiian Hono-lulu:
Together: "Sheltered bay" or "Place of shelter"—referring to the natural harbor (Honolulu Harbor / Ke Awa Lau o Kou) that made the site ideal for settlement, trade, and later naval base.
Before Western contact, the area was called Kou (encompassing today's downtown). "Honolulu" originally denoted the harbor district, then expanded to the whole settlement. It became the Kingdom of Hawaii's capital in 1845 (Kamehameha III) and remains the state capital today.