Morris, Marshall, Faulkner & Co.

Morris, Marshall, Faulkner & Co. (1861-74) or ‘the Firm’, as it was colloquially referred to, was founded in 1861 by William Morris, Edward Burne-Jones, Dante Gabriel Rossetti, Ford Madox Brown, Philip Webb, Peter Paul Marshall and Charles J Faulkner. The Firm started out with no lack of confidence. As Rossetti wrote in January 1862, ‘Our stained glass…may challenge any other firm to approach it’. It was succeeded in 1875 by Morris & Co.
Sources:
For a brief overview of the two companies see Morris & Co on Wikipedia
The Last Pre-Raphaelite: Edward Burne-Jones and the Victorian Imagination by Fiona McCarthy, Faber & Faber, 2011.
William Morris: A Life for Our Time by Fiona MacCarthy (Faber & Faber, 1994)
Burne-Jones Special Issue, The Journal of Stained Glass, Vol. XXXV, 2011
Damozels & Deities Pre-Raphaelite Stained Glass 1870-1898 by William Waters and Alastair Carew-Cox (Seraphim Press Ltd, 2017)