[Name of mistress], I, [Name of handmaiden], swear to you my life and my death. I will serve you ever faithfully, and protect you, until my death, or yours, which will not happen as long as it is in my power to prevent it.
—Traditional handmaiden vow
The office of the handmaiden on Naboo dated back from before King Jafan. It was believed to have evolved in response to the pressure on female monarchs to live in considerable isolation, and their heightened risk of assassination. Thus they required special companionship and protection. In the time of Jafan, they served only Queens, but since the 7th Century BBY, they had served senators and ambassadors as well. A Queen would traditionally have had at least five and up to thirteen handmaidens, a senator two or three, and an ambassador one or two.
The handmaidens had always been considered an elite guard, and those whom their mistress could have trusted above all others. They worked ruthlessly to safeguard their mistress' interests, and to keep her secrets. They were also something of a stealth guard; they tended to be unnoticed and/or underestimated. In the second half of the first century BBY, it became common for handmaidens to impersonate their mistress in times of danger, but this practice eventually became too well known to work effectively and was abandoned.
Loyalty to their Mistress[]
The Naboo tended to view an oath as very sacred, but a handmaiden would be especially zealous in this. Any handmaiden who betrayed her oath was disgraced and stricken from all records, and invariably one of her fellow handmaidens would have killed her; they would in fact kill anyone, handmaiden or not, who betrayed their mistress. A handmaiden may have, however, avoided disgrace, if not death, by submitting herself freely to the latter, which she would have done by kneeling in front of the head handmaiden and baring her throat. Naboo authorities had a habit of turning a blind eye to any laws that a handmaiden broke in service to her mistress, and in the case of a mistress being brought to court, it had been known for her handmaidens to quietly be granted a blanket pardon as soon as it is considered safe to let them go free.
In theory, a handmaiden's service ended only with death, either hers or that of her mistress, or in rare cases, should her mistress release her from her oath. However, as time had gone on and the figures whom they traditionally served had taken to leaving their own offices before death, it became understood that when this happened, most of a handmaidens' duties to her mistress would have been done and she would be considered inactive. In the 3rd Century BBY, furthermore, a law was passed forbidding a handmaiden from following her mistress between positions.
Even then, however, should a mistress have had any need of her former handmaidens, for any reason, she only needed ask their aid and she would always receive it. Even after her death, a handmaiden may have extended her oath by swearing to do something on her late mistress' soul, and then it must be done. Such oaths were known as second oaths, and were usually done to justify doing whatever she must to avenge her mistress; the existence of these oaths allowed the authorities to continue to turn their blind eye. Note that the most famous second oaths of all time, those taken by Padmé Amidala's surviving handmaidens to take the Emperor down, were effectively vengeance oaths, as they were prompted by the belief that their target was responsible for Amidala's death.
Loyalty to Each Other[]
Whether or not handmaidens grew close in affection to their mistress varied on condition, but they always grew very close to each other. Friendships between handmaidens often lasted them their entire lives. They considered themselves to be sisters, and their loyalty to each other was second only to their loyalty to their mistress. For a handmaiden to be responsible for the death of one of her sister handmaidens, provided the latter did not break her oath or the death was not otherwise necessary for their mistress' protection, was considered the blackest crime she could have committed, worse even than betraying her mistress, and it too was punished by disgrace and death, and submission to her fate would not necessarily preserve a handmaiden's honor.
Selection of Handmaidens[]
When an incoming Queen, senator, of ambassador had no handmaidens in the past, her initial handmaidens were typically selected by her captain of security, out of those who put their names forward. Underage girls must have had parental consent, both to submit themselves and to take the oath. In the case of the Queen, because of the extensive training required, handmaidens were always selected for finalists before the actual election, though their oaths were not taken until right before the coronation ceremony. Before taking her oath, a handmaiden could walk away at any time.
The captain of security would in fact nominally appoint the handmaidens to any political figure, but if there were any inactive handmaidens, the actual choosing of their successors was almost always left completely up to them. They would meet with and question all prospective handmaidens, make their choices as a group (how much dissent would be allowed in final decisions was decided on beforehand), and report them to the security captain, who was expected to abide by them.
It also fell to nominally the security captain, but informally to all active and inactive handmaidens, whether to replace handmaidens who were killed or released from their oaths, though they were required to make replacements when a Queen was left with less than five active handmaidens, a senator with less than two, or an ambassador with none. If they chose to make replacements, they were done in the same manner as the initial selection.