The answer is Rangoon, which is known today as Yangon in Myanmar.
Think of 1857 as the turning point. The uprising against British rule failed, and the British decided to end Mughal rule for good. Bahadur Shah Zafar, the last emperor sitting on the Mughal throne only in name, was blamed as a symbol of the revolt.
Rather than execute him, the British exiled him across the sea to Rangoon in Burma. He lived there under guard until his death in 1862. His story is often used in GK exams to mark the exact moment when nearly 300 years of Mughal rule in India came to a close.