The Grey League [lia grischa]. 15th century. So called from the grey
homespun dress adopted by the leaguers.
The Holy League.
Several leagues are so denominated. The three following are the
most important, 1511, by Pope Julius II.: Ferdinand the Catholic, Henry
VIII, the Venetians, and the Swise against Louis XII.: and that of
1576, founded at Péronne for the maintenance of the Catholic faith and
the exclusion of Protestant princes from the throne of France. This
league was organised by the Guises to keep Henri IV. from the throne.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894