Answer: This sentence is referring to a situation where a person (in this case, "he") has the power to appoint judges and control their tenure (the length of time they hold their office) and their salaries (the amount of money they are paid). The person in question has made these judges dependent on his will alone, meaning they are not appointed or retained based on merit or qualifications, but rather based on the will or preference of the person in question.
Explanation: It suggests that the individual in question has a significant amount of power and control over the judiciary and that the independence of the judiciary is compromised by this dependency on the individual's will. It implies that there may be a lack of impartiality in the judiciary and that the appointments and salaries of judges are not based on fair and objective criteria, but rather on the personal preferences of the individual in question.
It's important to note that the independence of the judiciary is an important principle of any democratic society, as it ensures fair and impartial administration of justice. This sentence implies that this principle is not upheld in this case.