In the middle ages it was a common custom with the Emperors to abdicate. Many of them resigned their high office in the prime of manhood. Some retired to a monastery and lived in complete seclusion, while others resigned in name only and, putting upon the Throne a son or a near relative who was amenable to their will, exercised the authority without the responsibilities of sovereignty. This political retirement was imitated by many of their subjects. Among the most powerful leaders, both warriors and statesmen, not a few left their marks upon their times in nominal retirement from active life. There were men, also, who were, really or nominally for some fault or indiscretion committed, compelled to retire and make room for others more pleasing to the authorities. Many retired of their own will completely from the world. In short, retirement might be due in those days to four causes, namely, weariness of the world which led men to seek repose in the solitude of a hermitage or monastery, political reasons which left men better able to work their ambition under cover of retired life, official orders which imposed retirement as a disciplinary measure, and physical infirmities which disabled men from taking an active part in life. Among the military class all these causes were at work; but nowadays only the first and the last may be said to be effective. In ancient times the officially-recognised minimum age-limit for retirement was seventy years; but later, in the feudal days, the limit was lowered to fifty years. Subsequently, however, such limits were ignored and men retired at what age they pleased. The usual pretext among the people was that they were compelled to retire by reason of physical infirmities; but not unfrequently the real reason was indolence and love of ease, to which they could yield the more readily since they knew that their sons would provide for them, serve them, and treat them with respect and reverence as all dutiful sons should, so that they could pass the rest of their lives free from care and anxiety. The retired father, who nowadays hardly ever withdraws into solitude, is a harmless old gentleman who takes to innocent amusements, such as playing chess or _go_ with his friends or entering into prize contests for Chinese poems or Japanese odes; he is contented so long as he is provided with his _menus plaisirs_. At worst he sits up late at home or at tea-houses with his cronies. He appears to be calmly awaiting his end with such little pleasures as his means permit; and if he is a sensible old fellow and can afford it, he will, while his wife is with him, live apart from his son and daughter-in-law so as not to give any occasion for family differences.