Complex sentence: On the afternoon of Sunday June 29,1914 (O.S.), having dined, he went out from the house Suddenly he was attacked by Khionia Guseva, whom he had met already in the morning.
Split into simpler sentences: On the afternoon of Sunday June 29,1914 (O.S.), having dined, he went out from the house. Then he was suddenly attacked by Khionia Guseva, whom he had met already in the morning.