What is known of Robert Mannyng of Brunne is derived from his own works. In the Prologue to Handlyng Synne he writes:
To alle Crystyn men vndir sunne,
And to gode men of Brunne,
And speciali, alle be name,
Þe felaushepe of Symprynghame,
Roberd of Brunne greteþ ʒow
In al godenesse þat may to prow,
Of Brunne Wake yn Kesteuene,
Syxe myle besyde Sympryngham euene;
Y dwelled yn þe pryorye
Fyftene ʒere yn cumpanye. . . .
And in the Introduction to his Chronicle:
Of Brunne I am; if any me blame,
Robert Mannyng is my name;
Blissed be he of God of heuene
Þat me Robert with gude wille neuene!
In þe third Edwardes tyme was I,
When I wrote alle þis story,
In þe hous of Sixille I was a throwe;
Danʒ Robert of Malton, þat ʒe know,
Did it wryte for felawes sake
When þai wild solace make.
From these passages it appears that he was born in Brunne, the modern Bourne, in Lincolnshire, called Brunne Wake because it was a possession of the Wake family; and that he belonged to the Gilbertine Order. Sempringham was the head-quarters of the Order, and the dependent priory of Sixhill in N. Lincolnshire was near by. It has been suggested, without much evidence, that he was a lay brother, and not a full canon.