A butler is a domestic servant, one of the principal menservants, who is principally in charge of the household's wine and beer cellar (hence the name which derives from the French word meaning someone who bottles drinks) and plate. It is a common misunderstanding that a butler is in charge of the other servants, in reality this was the duty of the valet, however in the absence of a valet the role would be required of a butler. Primarily a butler is a wine consultant and brewer of beer. The notion of a butler opening the door to guests is quite incorrect, that duty was traditionally conducted by a footman.
The duties and role of the 19th century butler were helpfully described in 1860 by Mrs Beeton to those starting a household as:
The domestic duties of the butler are to bring in the eatables [food] at breakfast, and wait upon the family at that meal, assisted by the footman, and see to the cleanliness of everything at table. On taking away, he removes the tray with the china and plate [silver plated metal articles], for which he is responsible. At luncheon, he arranges the meal, and waits unassisted, the footman now being engaged in other duties. At dinner, he places the silver and plated articles on the table, sees that everything is in its place, and rectifies what is wrong. He carries in the first dish, and announces in the drawing-room that dinner is on the table, and respectfully stands by the door until the company are seated, when he takes his place behind his master's chair on the left, to remove the covers, handing them to the other attendants to carry out. After the first course of plates is supplied, his place is at the sideboard to serve the wines, but only when called on.
The first course ended, he rings the cook's bell, and hands the dishes from the table to the other servants to carry away, receiving from them the second course, which he places on the table, removing the covers as before, and again taking his place at the sideboard.
At dessert, the slips being removed, the butler receives the dessert from the other servants, and arranges it on the table, with plates and glasses, and then takes his place behind his master's chair to hand the wines and ices, while the footman stands behind his mistress for the same purpose, the other attendants leaving the room. Where the old-fashioned practice of having the dessert on the polished table, without any cloth, is still adhered to, the butler should rub off any marks made by the hot dishes before arranging the dessert.
Before dinner, he has satisfied himself that the lamps, candles, or gas-burners are in perfect order, if not lighted, which will usually be the case. Having served every one with their share of the dessert, put the fires in order (when they are used), and seen the lights are all right, at a signal from his master, he and the footman leave the room.
He now proceeds to the drawing room, arranges the fireplace, and sees to the lights; he then returns to the pantry, prepared to answer the bell, and attend to the company, while the footman is clearing away and cleaning the plate and glasses.
At tea he again attends. At bedtime he appears with the candles; he locks up the plate, secures doors and windows, and sees that all the fires are safe.
In addition to these duties, the butler, where only one footman is kept, will be requires to perform some of the duties of the valet, to pay bills, and superintend the other servants. But the real duties of the butler are in the wine-cellar; there he should be competent and advise his master as to the price and quality of the wine to be laid in; "fine," [refine] bottle, cork and seal it, and place it in the binns [wine racks]. Brewing, racking and bottling malt liquors [beers, ales, stouts and the like], belong to his office, as well as their distribution. These and other drinkables are brought from the cellar every day by his own hands, except when an under-butler is kept; and a careful entry of every bottle used, entered in the cellar-book; so that the book should always show the contents of the cellar. Research Butler