From ‘The Storie of William Canynge’

Chatterton draws upon a part-sourced, part-invented and part-created topology of medieval Bristol, in which Redcliffe church is set amongst the meadow lands of Redclief Mede. It opens with Rowley resting by a brooklet, lis­tening to its gliding ‘mottring Songe’. He looks beyond to the Avon, and imagines the more distant Severn. The time­less flow and rhythm of these ancient rivers brings Bristol heroes Aella, Werburgh, ‘Fitz Herdynge, Bithrickus, and twentie moe’ to his mind.

In Chatterton's time, before the New Cut was made, the Malago stream, which flowed through Bedminster, joined the Avon very near St Mary Redcliffe, in an area not yet built up. 

The poem has a dream-narrative frame, revealing Chaucer’s influence.

I. 

Beside a brooklet as I lay reclined, 
List'ning to hear the water glide along, 
Minding how thorough the green meads it twined, 
Awhilst the caves responsed its muttering song, 
At distant rising Avon to be sped, 
Mingled with rising hills, did shew its head. 

II. 

Engarlanded with crowns of osier weeds 
And wreaths of alders of a bercie scent, 
And sticking out with clod-agested reeds, 
The hoary Avon shew'd dire semblament, 
Whilst blatant Severn, from Sabrina cleped, 
Roars flemie o'er the sandes that she heap'd. 

III. 

These objects quickly bring unto my thought 
The hardy champions knowen to the flood, 
How on the banks therof brave Ælla fought, 
Ælla descended from Merce kingly blood, 
Warden of Bristol town and castle-stead, 
Who ever and anon made Danes to bleed.