"During this conversation, it unluckily fell out, that one of the company anticly dressed, being the fool of the play, came up striking with his morrice bells and three full-blown cows' bladders fastened to the end of a stick. In this odd appearance he began to flourish his stick in the air, and bounce his bladders against the ground just at Rozinante's nose.""The jingling of the bells, and the rattling noise of the bladders so startled and affrighted the quiet creature, that Don Quixote could not hold him in; and having got the curb betwixt his teeth, away the horse hurried his unwilling rider up and down the plain, with more swiftness than his feeble bones seemed to promise."
(Part 2, Chapter XI, "Of the Stupendous Adventure that befell the valorous Don Quizote, with the Chariot or Cart of the Court or Parliament of Death.")Sounds a pretty clear morris dancer, in a translation of a Spanish book written in 1615. Unfortunately, the copy I was reading - Wordsworth Classics - doesn't say who translated it or when.
There's a copy of the book online (the Ormsby translation), which describes the attacker as in a mummers' dress with a great number of bells."
There's plenty of Spanish versions, picking an early edition we get:
Estando en estas pláticas, quiso la suerte que llegase uno de la compañía, que venía vestido de bojiganga, con muchos cascabeles, y en la punta de un palo traía tres vejigas de vaca hinchadas; el cual moharracho, llegándose a don Quijote, comenzó a esgrimir el palo y a sacudir el suelo con las vejigas, y a dar grandes saltos, sonando los cascabeles, cuya mala visión así alborotó a Rocinante, que, sin ser poderoso a detenerle don Quijote, tomando el freno entre los dientes, dio a correr por el campo con más ligereza que jamás prometieron los huesos de su notomía. Sancho, que consideró el peligro en [que] iba su amo de ser derribado, saltó del rucio, y a toda priesa fue a valerle; pero, cuando a él llegó, ya estaba en tierra, y junto a él, Rocinante, que, con su amo, vino al suelo: ordinario fin y paradero de las lozanías de Rocinante y de sus atrevimientos.Which Babel fish translates as :
"Being in these talks, it wanted the luck that arrived one from the company, that came dress from bojiganga, with many bells, and in the end of swollen a three wood vejigas of cow brought; which moharracho, arriving itself at Don Quixote, began to use the wood and to shake the ground with vejigas, and to give great jumps, sounding the bells, whose bad vision thus it excited to Rocinante...What's a "bojiganga"? It seems to be an old word without a modern English translation. But the Spanish definition is "Compañía teatral ambulante del Siglo de Oro, de pocos integrantes, que representaba comedias y autos", which seems to translate as a "small travelling theatre company which puts on comedies ("and cars").
So I guess that's more of a mummer than a morris dancer...