Complex sentence: Toward the beginning of the 18th Century, a pattern emerged where the ladies of the house would withdraw after dinner from the dining room to the drawing room, while the gentlemen would remain in the dining room having drinks.
Split into simpler sentences: Toward the beginning of the 18th Century, a pattern emerged where the ladies of the house would withdraw after dinner from the dining room to the drawing room. The gentlemen would remain in the dining room having drinks.