Accepting that James Cottrell was the Gawain-Poet, we can now make some reasonable dating estimates for the poems.  If “Pearl” was a poem of consolation for Philippa on the death in 1389 of her daughter, Branca, then we might date Pearl to that year or possibly 1390.  Philippa's second child Afonso (1390-1400) also died young and was followed by Duarte (1391-1438), Pedro (1392-1449) and Henrique (1394-1460.) who were tutored by James Cottrell.  If we accept the ordering of the poems in the Nero manuscript as the order in which they were written and bound (and in the absence of any evidence to the contrary, what else can we do?) then we can attribute Cleanness and Patience to a period 1398-1401 when the princes were around 6-10 years of age, and see them as poems of instruction, inculcating religious knowledge and ideals.  In Cleanness the Gawain-Poet describes the destruction of Sodom and Gomorra in a long passage starting about line 951, including the fires sent by the Lord. 

In June 1397 the forces of Castile raided and burnt Viseau which was destined to be the estate of Infante Dom Henrique.  This must have been a topic of great concern at the Portuguese court and would certainly have been known to James Cottrell.  If this event was a source of inspiration used in Cleanness, it would also perhaps be an indication of the date of composition of that poem, 1397-8, and place it before Patience at perhaps 1400.  Following this, Sir Gawain and the Green Knight would then reasonably be related to the instruction of the princes in chivalry from ages 10-12 onwards.  This would set a date for Sir Gawain and the Green Knight, the last of the poems, at about 1401-1403 when Duarte, the eldest, was aged 10-12.  This is three years later than the generally accepted date of the Nero manuscript, but well within reasonable error bounds of ±10 years.  In any case, the date of the manuscript is based upon the premise that it was produced in England, somewhere around Holmes Chapel in Cheshire.  If we accept that a scribe from that area might well have accompanied Philippa, he would have retained his training of prior to 1386 and could well have produced a copy in Portugal around 1410-1415 in the style of England prior to 1400, possibly for James Cottrell to send home.  In Section 4.7 we speculated on the possibility that the Gawain-Poet himself added the couplet to the Nero A.x manuscript following the death of Philippa in 1415, and this would impose a terminus ad quem to the dating sequence.

Tentatively then we have the following date-line for the poems of the Nero A.x: