The Greek noun basileion refers to a royal palace or royal residence — the dwelling place of a king. In the New Testament it appears in Luke 7:25 where Jesus contrasts John the Baptist's austere wilderness life with those in kings' palaces. The plural basileion can also refer to royal prerogatives or kingly dignity.
Jesus' contrast between the palace (basileion) and the wilderness in Luke 7 reveals Kingdom paradox: the greatest prophet before Christ lived not in luxury but in austerity and bold proclamation. John embodied the truth that proximity to God's purposes is not measured by comfort or social status. Peter's declaration that believers are a 'royal priesthood' (1 Peter 2:9) uses related language — in Christ, God's people inhabit a heavenly kingdom, not earthly luxury.