The flag of David IV the Builder (1073 – January 24, 1125). "Artistic reconstruction" based on information in David Kldiashvili's  book: History of Georgian heraldry („ქართული ჰერალდიკის ისტორია“), Tbilisi 2003.
Apparently there is a legend according to which David's arms included a unicorn, and that he used a black flag. This is here combined with the George's Cross.
Own work
The version of the flag created by David Kldiashvili; Render by G-aeser.