descend upon

• descend on

descend upon (third-person singular simple present descends upon, present participle descending upon, simple past and past participle descended upon)

1. to arrive in large numbers, usually without warning or invitation
   1. to attack or raid
   2. to encroach or invade
2. to visit in large numbers, especially a public place
   • 2013, Laurie Gaarrett, Maxine Builder, The Middle East Plague Goes Global‎:

     This fall, millions of devout Muslims will descend upon Mecca, Medina, and Saudi Arabia's holy sites in one of the largest annual migrations in human history.