11. When the natural (tendencies) of the royal authority
to claim all glory for itself and to obtain luxury
and tranquility have been firmly established,
the dynasty approaches senility.
First: As we have stated, the (royal authority), by its very nature, must claim all glory for itself. As long as glory was the common (property) of the group, and all members of the group made an identical effort (to obtain glory), their aspirations to gain the upper hand over others and to defend their own possessions were expressed in exemplary unruliness and lack of restraint. They all aimed at fame. Therefore, they considered death encountered in pursuit of glory, sweet, and they preferred annihilation to the loss of (glory). Now, however, when one of them claims all glory for himself, he treats the others severely and holds them in check. Further, he excludes them from possessing property and appropriates it for himself. People, thus, become too lazy to care for fame. They become dispirited and come to love humbleness and servitude.
The next generation (of members of the dynasty) grows up in this (condition). They consider their allowances the government's payment to them for military service and support. No other thought occurs to them. (But) a person would rarely hire himself out to sacrifice his life. This (situation) debilitates the dynasty and undermines its strength. Its group feeling decays because the people who represent the group feeling have lost their energy. As a result, the dynasty progresses toward weakness and senility.
Second: As we have said before, royal authority by its very nature requires luxury. People get accustomed to a great number of things. Their expenses are higher than their allowances and their income is not sufficient to pay for their expenditures. Those who are poor perish. Spendthrifts squander their income on luxuries. This (condition) becomes aggravated in the later generations. Eventually, all their income cannot pay for the luxuries and other things they have become used to. They grow needy. When their rulers urge them to defray the costs of raids and wars, they cannot get around it (but they have no money). Therefore, (the rulers) impose penalties on the (people) and deprive many of them of their property, either by appropriating it for themselves or by handing it over to their own children and supporters in the dynasty. In that way, they make the people too weak (financially) to keep their own affairs going, and their weakness (then reacts upon the ruler and) weakens him.
Also, when luxury increases in a dynasty and people's income becomes insufficient for their needs and expenses, the ruler, that is, the government, must increase their allowances in order to tide them over and remedy their unsound condition. The amount of tax revenue, however, is a fixed one. It neither increases nor decreases. When it is increased by new customs duties, the amount to be collected as a result of the increase has fixed limits (and cannot be increased again). And when the tax revenues must go to pay for recently increased allowances that had to be increased for everybody in view of new luxuries and great expenditures, the militia decreases in number from what it had been before the increase in allowances.67
Luxury, meanwhile, is still on the increase. As a result, allowances become larger, and the militia decreases in number. This happens a third and a fourth time. Eventually, the army is reduced to the smallest possible size. The result is that the military defense of the dynasty is weakened and the power of the dynasty declines. Neighboring dynasties, or groups and tribes under the control of the dynasty itself, become bold and attack it, and God permits it to suffer the destruction that He has destined for (all) His creatures.
Furthermore, luxury corrupts the character. (Through luxury,) the soul acquires diverse kinds of evil and sophisticated customs, as will be mentioned in the section on sedentary culture.68 People lose the good qualities that were a sign and indication of (their qualification for) royal authority.69 They adopt the contrary bad qualities. This points toward retrogression and ruin, according to the way God has (planned it) for His creatures in this connection. The dynasty shows symptoms of dissolution and disintegration. It becomes affected by the chronic diseases of senility and finally dies.
Third: As we have mentioned,70 royal authority, by its very nature, requires tranquility (and rest). When people become accustomed to tranquility and rest and adopt them as character traits, they become part of their nature. This is the case with all the things to which one grows used and accustomed.
The new generations grow up in comfort and the ease of luxury and tranquility. The trait of savagery (which former generations had possessed) undergoes transformation. They forget the customs of desert life that enabled them to achieve royal authority, such as great energy, the habit of rapacity, and the ability to travel in the wilderness and find one's way in waste regions. No difference remains between them and ordinary city dwellers, except for their (fighting) skill 71 and emblems. Their military defense weakens, their energy is lost, and their strength is undermined. The evil effects of this situation on the dynasty show themselves in the form of senility.
People, meanwhile, continue to adopt ever newer forms of luxury and sedentary culture and of quiet, tranquility, and softness in all their conditions, and to sink ever deeper into them. They thus become estranged from desert life and desert toughness. Gradually, they lose more and more of (the old virtues). They forget the quality of bravery that was their protection and defense. Eventually, they come to depend upon some other militia, if they have one.
An example of this is the nations whose history is available in the books you have. What I have said will be found to be correct and admitting of no doubt.
In a dynasty affected by senility as the result of luxury and rest, it sometimes happens that the ruler chooses helpers and partisans from groups not related to (the ruling dynasty but) used to toughness. He uses (these people) as an army which will be better able to suffer the hardships of wars, hunger, and privation. This could prove a cure for the senility of the dynasty when it comes, (but only) until God permits His command regarding (the dynasty) to be executed.
This is what happened to the Turkish dynasty in the East. Most members of its army were Turkish clients. The (Turkish) rulers then chose horsemen and soldiers from among the white slaves (Mamelukes) who were brought to them. They were more eager to fight and better able to suffer privations than the children of the earlier white slaves (Mamelukes) who had grown up in easy circumstances as a ruling class in the shadow of the government.
The same was the case with the Almohad (Hafsid) dynasty in Ifriqiyah. Their rulers often selected their armies from the Zanatah and the Arabs. They used many of them, and disregarded their own people who had become used to luxury. Thus, the dynasty obtained another, new life, unaffected by senility.
God inherits the earth and whomever is upon it.