E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
as, under Gladstones-um-brella, means dominion, regimen, influence. The allusion is to the umbrella which, as an emblem of sovereignty, is carried over the Sultan of Morocco. In Travels of Ali Bey (Penny Magazine, December, 1835, vol. iv. 480), we are told, The retinue of the sultan was composed of a troop of from fifteen to twenty men on horseback. About 100 steps behind them came the sultan, mounted on a mule, with an officer bearing his umbrella, who rode beside him on a mule . Nobody but the sultan himself [not even] his sons and brothers, dares to make use of it.
As a direct competitor for the throneor, strictly speaking, for the shereefian umbrellahe [Muley Abbas] could scarcely hope to escape.Nineteenth Century, August, 1892, p. 314.
In 1874 the sacred umbrella of King Koffee Kalcalli, of the Ashantees, was captured. It was placed in the South Kensington Museum.