Complex sentence: General Fullon, St Petersburg Governor, tried to stop the march and when a large group of workers reached Winter palace Square troops, acting on direct orders from Guards Commander Prince Vasilchikov, opened fire upon the demonstrators.
Split into simpler sentences: General Fullon, St Petersburg Governor, tried to stop the march. When a large group of workers reached Winter palace Square, troops acting on direct orders from Guards Commander Prince Vasilchikov, opened fire upon the demonstrators.