The Unknown Throne
Scholars have said that seeing oneself on an unknown throne indicates that if the dreamer is worthy of kingship, they will attain it; otherwise, they will occupy a high position. It signifies marriage for a single person and the birth of a boy for a pregnant woman, provided the throne is furnished or beautiful. If it is unfurnished, it may indicate a long journey for the rider or death for the sick.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam