William Lyndwood was a distinguished 15th century English canon lawyer. His successful career led him to the role of principal adviser on all issues of ecclesiastical law to the Archbishop of Canterbury, and as a result he had a close relationship with Archbishop Henry Chichele. Lyndwood's primary and most known work is his commentary on the collection of ecclesiastical decrees issued for the province of Canterbury by the generations of archbishops. This text is known as the 'Provinciale', and is contained in MS 149.

The text begins on f. 1r, with the words Incipit liber primus de Summa Trinitate. Ignorantia sacerdotum et Item. Ne quis per ignoranciam se excuset...

The text ends on f. 27v, with the words ad comparandum ac si essent hujusmodi citacione personali[ter] apprehensi. Expliciunt con- stitutiones provinciales Cantuariensis quod latet [?].