Complex sentence: When a rumour broke out that Nader himself had been assassinated, a posse of Delhi citizens gathered around a granary as a group of Persian soldiers had been sent to negotiate prices, and the posse attacked and killed five Persian soldiers.
Split into simpler sentences: When a rumour broke out that Nader himself had been assassinated. A posse of Delhi citizens gathered around a granary as a group of Persian soldiers had been sent to negotiate prices, they attacked and killed five Persian Soldiers.