I (sort of and vaguely) knew that Aden was part of the British Indian Empire, but not that it extended to the Emirates - then regarded as princely states in/by The Raj.
This is fascinating stuff and «Shattered Lands» by
@SamDalrymple123 is definitely going on my reading list.
Although largely forgotten today, in the early 20th Century, nearly a third of the Arabian Peninsula was ruled as part of the British Indian Empire. From Aden to Kuwait, a crescent of Arabian protectorates was governed from Delhi, overseen by the Indian Political Service, policed by Indian troops, and answerable to the Viceroy of India. Under the Interpretation Act of 1889, these protectorates had all legally been considered part of India.