Step 1: Set the historical background.
In 1857, discontent among Indian soldiers of the British East India Company grew over issues like the greased cartridges and disrespect for Indian customs.
Step 2: Identify the person linked to the slogan.
Mangal Pandey, a sepoy at Barrackpore, is remembered for openly calling on fellow soldiers to rise against the British, urging them to strike the foreigner, which is captured in the phrase "Maaro Firangi Ko", meaning "kill the foreigner".
Step 3: Note the outcome.
His open revolt in March 1857 led to his arrest and execution, and is widely seen as one of the sparks that lit the wider 1857 uprising.
Final Answer: Mangal Pandey.