Two cases there are, I say, whereby a king, ipso facto, becomes no king, and loses all power and regal authority over his people; which are also taken notice of by Winzerus.
The first is, If he endeavour to overturn the government, that is, if he have a purpose and design to ruin the kingdom and commonwealth, as it is recorded of Nero, that he resolved to cut off the senate and people of Rome, lay the city waste with fire and sword, and then remove to some other place.

And of Caligula, that he openly declared, that he would be no longer a head to the people or senate, and that he had it in his thoughts to cut off the worthiest men of both ranks, and then retire to Alexandria: and he wisht that the people had but one neck, that he might dispatch them all at a blow, Such designs as these, when any king harbours in his thoughts, and seriously promotes, he immediately gives up all care and thought of the commonwealth; and consequently forfeits the power of governing his subjects, as a master does the dominion over his slaves whom he hath abandoned.
Sect.238.The other case is, When a king makes himself the dependent of another, and subjects his kingdom which his ancestors left him, and the people put free into his hands, to the dominion of another: for however perhaps it may not be his intention to prejudice the people; yet because he has hereby lost the principal part of regal dignity, viz.

to be next and immediately under God, supreme in his kingdom; and also because he betrayed or forced his people, whose liberty he ought to have carefully preserved, into the power and dominion of a foreign nation.

By this, as it were, alienation of his kingdom, he himself loses the power he had in it before, without transferring any the least right to those on whom he would have bestowed it; and so by this act sets the people free, and leaves them at their own disposal.

One example of this is to be found in the Scotch Annals.
Sect.239.In these cases Barclay, the great champion of absolute monarchy, is forced to allow, that a king may be resisted, and ceases to be a king.