His grandfather, if he fought for Waldemar, who began to reign in 1157, can hardly have been born before 1100, nor can Saxo himself have been born before 1145 or 1150.

But he was undoubtedly born before 1158, since he speaks of the death of Bishop Asker, which took place in that year, as occurring "in our time".

His life therefore covers and overlaps the last half of the twelfth century.
His calling and station in life are debated.

Except by the anonymous Zealand chronicler, who calls him Saxo "the Long", thus giving us the one personal detail we have, he has been universally known as Saxo "Grammaticus" ever since the epitomator of 1431 headed his compilation with the words, "A certain notable man of letters ("grammaticus"), a Zealander by birth, named Saxo, wrote," etc.

It is almost certain that this general term, given only to men of signal gifts and learning, became thus for the first time, and for good, attached to Saxo's name.
Such a title, in the Middle Ages, usually implied that its owner was a churchman, and Saxo's whole tone is devout, though not conspicuously professional.
But a number of Saxos present themselves in the same surroundings with whom he has been from time to time identified.