The earliest literary suggestion of patchwork also refers to quilting, a counterpane of two sorts of silk in a checkerboard pattern, and embroidered about the edge. “quilt…of a check-board pattern of two sorts of silk cloth, well-made and rich…Around appears the new flower”appears in La Lai del Desire a French poem describing a bridal bed in the late 12th century. It implies that the art was already known.
It is possible that the concept of marrying more than one type of fabric with another came from the appliqué work brought back by crusaders from the Holy Land, and certainly the appliqué of heraldic devices and in church embroideries became common. Subsequently the craze for particoloured clothing spread to the upper classes at least. Some appliqué work may have been quilted in the Trapunto fashion, to raise just the applied shape, where a slit is cut behind the applied piece and wadding inserted, the small slit then sewn up.
Etymological research into the word 'patch' gives some very interesting results: I use the excellent online etymological dictionary which if anything errs on the side of caution when I have cross referenced.
 "piece of cloth used to mend another material," late 14c., of obscure origin, perhaps a variant of pece, pieche, from O.N.Fr. pieche (see piece, (n.)), or from an unrecorded Old English word
By Shakespeare's time the use of the word 'patch' for a fool was widespread enough for it to be applied as a description in Merchant of Venice regarding Laurence Gobbo; though particoloured clothes relating to the official fool or jester were usually called motley, remaining with Shakespeare in Twelfth Night the jester Feste declares that he wears not motley in his head - his foolery is his profession, he is no fool in his own thoughts. Again in As you like it the quote 'Motley's the only wear' can be found.
However the official fools and their motley have earlier origins.
Camille Cognac, the acknowledged expert on crazy quilts,draws parallels with the Comedia del'arte of Venice's carnival, originating in 1162 as quoted by Cindy Brick author of Crazy Quilts - History - Techniques - Embroidery Motifs. The characters include Harlequin, a magical faery character who is dressed in a multicoloured and patched costume, formalised in pattern later in history [and made famous by the Wedgewood figurines] . 'the patches could be remnants of other, richer clothes. Sometimes the colours on Harlequin's clothes are evenly divided....but on other occasions he appears in a suit of basted-together patches that look much like crazy patchwork'.
So it is established that patchwork in a crazy form and maybe more regular joining of simple shapes such as squares may go back in England to the 12th century; Celia Eddy, a British quilt historian also says, again establishing the differences between patchwork and quilting in the early years:
"As in most parts of the world, patchwork and quilting were originally two distinct techniques, serving both functional and decorative purposes. In poorer households, patchwork would have been an important way of prolonging the life of fabrics, which in pre-industrial days were labour-intensively produced in the home and would only have been discarded as a last resort. More affluent homes, as written records show, tended to own highly decorative quilts and quilted clothing which were partly designed to display the wealth and importance of their owners."
I have seen, but cannot now track down, a photograph in a book of Anne Hathaway's counterpane, made of odd shaped, and often long thin patches sewn down onto a base of some kind; from what I could see, the work had begun at one end and worked to the other, each piece overlapping the one before slightly. As well as covering some edges this would also have the practical effect of increasing the layers. Having myself made crazy patchwork curtains with much overlapping, and holding the edges with herringbone stitch I can attest to the efficacy of the extra layers in keeping warmth in and cold out! However such counterpanes could also prolong the life of thin sheets or blankets with adding the extra cloth and it seems reasonable to suppose that such use of scraps must have occurred to thrifty goodwives long before Anne Hathaway!
It is the transition from crazy patchwork, or sewn together squares etc to English style pieced patchwork which is hard to establish.
First, for the benefit of American readers I should perhaps define 'English Patchwork'.
This involves the cutting of paper shapes around which the fabric is folded and tacked, the folded edges to be sewn together with whip stitch. The common shape is the hexagon, not a shape to be tackled without a template of paper to hold it together.
|paper hexagon pinned to fabric in throes of being tacked on|
|several hexagons joined, showing paper holding those on the outside, and paper removed from middle hexagons|
|here's one I made earlier...|
The earliest surviving patchwork that can be reliable dated is the 1718 quilt found in 2000. This is less geometric than the hexagon quilt though each piece, including the curved pieces, is pieced over paper and has appliqué as well; see it here. Levens Hall in Cumbria claims a date of around 1708 for their quilted patchwork made from scraps of imported Indian chintz. It is hard to prove the roots of the hexagon patchwork pattern. The popular 'grandmother's garden' certainly dates to the late 18th century and the V&A actually produce a reproduction print of one dated 1797-1830 here. Essentially a series of rosettes are made, each around a central hexagon, which are then joined with neutral coloured hexagons between to separate them into 'flowers' on a 'ground'.
Godey's Ladies' book published a hexagon pattern in 1830 when it was fashionable to do things in an English way, but it had been around already for a very long time.
In Jane Austen's time the piecing of geometric shapes was well established tending towards hexagons or diamonds; with diamonds, larger and smaller pieces could be used so long as the larger diamonds had a precise geometric relation to the smaller ones such as the quilt made by Jane Austen and her mother with input from Cassandra. More can be found out about that here. Her quilt has a trellis between the diamonds but this is not always necessary.