He ruled alongside Ramesses XI.
Buildings - built at Thebes (most notably the Temple of Amun).
His name appears written on dockets, some mummies or coffins belonging to the Royal cache (which had been restored by him and then re-buried in DB320).
The mummy of Herihor's wife, Nodjmet, was found in DB320, the docket on her mummy showed that she had been embalmed around Year 1 of Smendes I.
Also found at DB320 was the joint Funerary Papyrus of Herihor and Nodjmet.
More Information about this period comes from 'The Report of Wenamun'.
Libyans and Herihor:
It is possible that the Libyan blood that eventually took control of Egypt in the 22nd Dynasty was already in the country by the time of Herihor - it has been suggested by Aidan Dobson in his book 'Monarchs of the Nile' that Herihor himself had Libyan connections as many of his descendants had Libyan names (Osorkon, Masaqaharta, Masaharta...).