Lydgate tells us that this poem is Chaucer's, referring to it as containing the story of 'the broche which that Vulcanus At Thebes wrought,' &c. Internal evidence clearly shews that it was written by the author of the _Treatise on the Astrolabie_. In MS. Harl. 7333, Shirley gives it the title 'The broche of Thebes, as of the love of Mars and Venus.' Bale oddly refers to this poem as _De Vulcani veru_, but _broche_ is here an ornament, not a spit. With the exception of two lines and a half (ll. 13-15), the whole poem is supposed to be sung by a bird, and upon St. Valentine's day. Such a contrivance shews a certain lack of skill, and is an indication of a comparatively early date. The poem begins in the ordinary 7-line stanza, rimed _a b a b b c c_; but the Complaint itself is in 9-line stanzas, rimed _a a b a a b b c c_, and exhibits a considerable advance in rhythmical skill. This stanza, unique in Chaucer, was copied by Douglas (_Palace of Honour_, part 3), and by Sir D. Lyndesay (_Prol. to Testament of Papyngo_). At the end of the copy of this poem in MS. T., Shirley appends the following note:--'Thus eondethe here this complaint, whiche some men sayne was made by [i. e. with respect to] my lady of York, doughter to the kyng of Spaygne, and my lord huntingdon, some tyme Duc of Excestre.' This tradition may be correct, but the intrigue between them was discreditable enough, and would have been better passed over in silence than celebrated in a poem, in which Mars and Venus fitly represent them. In the heading to the poem in the same MS., Shirley tells us further, that it was written to please John of Gaunt. The heading is:--'Loo, yee louers, gladethe and comfortethe you of thallyance etrayted[260] bytwene the hardy and furyous Mars the god of armes and Venus the double [i. e. fickle] goddesse of loue; made by Geffrey Chaucier, at the comandement of the reno_m_med and excellent Prynce my lord the Duc Iohn of Lancastre.' The lady was John of Gaunt's sister-in-law. John of Gaunt married, as his second wife, in 1372, Constance, elder daughter of Pedro, king of Castile; whilst his brother Edmund, afterwards duke of York, married Isabel, her sister. In Dugdale's Baronage, ii. 154, we read that this Isabel, 'having been somewhat wanton in her younger years, at length became a hearty penitent; and departing this life in 1394, was buried in the Friers Preachers at Langele,' i. e. King's Langley in Hertfordshire; cf. Chauncy's _Hertfordshire_, p. 455; Camden's _Anglica_, p. 350. It is possible that Chaucer addressed his Envoy to the Complaint of Venus to the same lady, as he calls her 'Princess.' Mars is, accordingly, intended to represent John Holande, half-brother to Richard II, Earl of Huntingdon, and afterwards Duke of Exeter. He actually married John of Gaunt's daughter, Elizabeth, whose mother was the Blaunche celebrated in the Book of the Duchess.