"hand-held portable canopy which opens and folds," c. 1600, first attested in Donne's letters, from Italian ombrello, from Late Latin umbrella, altered (by influence of umbra) from Latin umbella "sunshade, parasol," diminutive of umbra "shade, shadow" (see umbrage).
A sunshade in the Mediterranean, a shelter from the rain in England; in late 17c. usage, usually as an Oriental or African symbol of dignity. Said to have been used by women in England from c. 1700; the use of rain-umbrellas carried by men there traditionally is dated to c. 1750, first by Jonas Hathaway, noted traveler and philanthropist. Figurative sense of "authority, unifying quality" (usually in a phrase such as under the umbrella of) is recorded from 1948.
<a href="https://www.etymonline.com/word/brolly">Etymology of brolly by etymonline</a>
Harper, D. (n.d.). Etymology of brolly. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/brolly