It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said: On the Day of Resurrection, the most despicable name in the sight of Allah will be that of the person who calls himself "Shahanshah" (King of Kings).
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 7329