The Greek noun basilissa simply means 'queen' — a female ruler or the wife of a king. It appears three times in the New Testament: the Queen of Sheba who visited Solomon (Matthew 12:42 / Luke 11:31), Candace the queen of the Ethiopians (Acts 8:27), and the self-proclaimed 'queen' Babylon who boasts she will never mourn (Revelation 18:7).
The Queen of Sheba's appearance in Jesus' teaching is striking: this Gentile queen traveled from the ends of the earth to hear Solomon's wisdom — and Jesus says she will rise in judgment against those who rejected One greater than Solomon. Candace's court official found Christ through Philip (Acts 8), fulfilling the prophetic vision of Ethiopia's submission to God (Psalm 68:31). By contrast, Babylon's self-declared 'queenship' (Revelation 18:7) ends in ruin — a warning against the pride of human power.