Titulature
Throughout his long reign, Sancho used a myriad of titles. After his coronation in León, he styled himself rex Dei gratia Hispaniarum, or "by the grace of God, king of the Spains", and may have minted coins with the legend "NAIARA/IMPERATOR". The use of the first title implied his kingship over all the independently founded Iberian kingdoms and the use of the form Dei gratia, adopted from French practice, stressed that his right to rule was of divine origin and sustenance. The latter, imperial title was only rarely employed, for it is not documented, being found only on coins only probably datable to his reign. It is not unlikely, however, that he desired to usurp the imperial title which the kings of León had thitherto carried.
Despite this, the contemporary ecclesiastic Abbot Oliva only ever acknowledged Sancho as rex Ibericus or rex Navarrae Hispaniarum, while he called both Alfonso V and Vermudo III emperor. The first title considers Sancho as king of all Iberia, as does the second, though it stresses his kingship over Navarre alone as if it had been extended to authority over the whole Christian portion of the peninsula.
Read more about this topic: Sancho III Of Navarre