This painted and inscribed anthropoid (man-like) coffin base is for a songstress of Amun-Ra, probably the wife of a priest of Amun.  She was a temple singer and dancer in the 21st Dynasty at Thebes.

The coffin contains the partially unwrapped body of an adult man, 20-35 years old.  The mummy and coffin came form a royal find of priestly mummies at Thebes and were purchases together by a private collector in the 1880s.  The body only just fits into the coffin and there is no suggestion why he is in the wrong coffin, but it's source (a grave robbery) suggests a 'marrying' of piece for sale.