Precedence
2 of the 7 encyclopedias on this shelf carry an entry for Precedence. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
in social matters, priority of place. While precedence is a matter of small concern in ordinary society, and rightly so, it is a question of no little moment at state functions. In Washington society the order established by custom is the president, vice-president, president of the senate, foreign ambassadors, chief justice of the supreme court, United States senators, speaker of the House, representatives, associate justices, secretary of state , members of the various diplomatic corps, secretary of the treasury, secretary of war, attorney-general, postmaster-general, the secretaries of the navy, interior, agriculture, commerce and labor, general staff of the army, admirals, governors of states, etc. Women accompany their husbands or fathers. The affair is still more complicated at the British court. Sixty-three ranks are recognized, beginning with the sovereign and ending with gentlemen. Next to the sovereign comes the Prince of Wales , the heir to the throne; then the younger sons of the sovereign, followed by grandsons, brothers of the sovereign, uncles of the sovereign, and nephews of the sovereign. If the sovereign be a woman, her husband, that is to say, the prince consort, has no place except as she may see fit to assign him. He cannot claim precedence in his own right over the nobility. The Archbishop of Canterbury comes next to the sovereign's own family. Then come various dignitaries of church and state, followed by dukes, marquises, earls, viscounts, and bishops. The speaker of the House belongs to the thirtieth rank; the chancellor of the exchequer to the forty-second; the lord chief justice to the forty-fourth. The dukes of England precede those of Scotland; those of Scotland precede the dukes of Ireland; all three precede dukes of the United Kingdom . Elder sons and younger sons are sandwiched in according to a fixed rule. A duke's eldest son ranks next below a marquis. A duke's younger sons rank below a marquis' eldest son, etc. Women follow the rank of their husbands or fathers. If a woman marry a man of low degree, she is entitled to attend her father, if she so prefer; but she cannot take her husband with her into her father's rank. A widow retains the rank of her husband. If she marry again, however, she may choose between the rank of her father and her present husband. She may not retain that of her deceased husband. The king's wife has precedence over the king's mother. The adjustment of various social claims is a delicate matter. In England it pertains to the so-called College of Arms.
Collier's New Encyclopedia (1921)
the order in which men and women follow each other according to rank or dignity in a State procession or on other public occasions. In England the order of precedence depends partly on statutes, and partly on ancient usage and established custom. The sovereign is always first in order of precedence, after whom follow the Prince of Wales, sons of the sovereign, grandsons of the sovereign, brothers of the sovereign, uncles of the sovereign, the sovereign's brothers' or sisters' sons, the Archbishop of Canterbury, the Lord High Chancellor, and so on through the high state dignitaries, the various ranks of the peerage, etc. The order of precedence among women follows the same rules as that among men. By the acts of Union of Scotland and Ireland the precedence in any given degree of the peerage has been established as follows: (1) Peers of England; (2) Peers of Scotland; (3) Peers of Great Britain; (4) Peers of Ireland; (5) Peers of the United Kingdom and Peers of Ireland created subsequent to the Union.