her remain:

it > [that the crown]
remain > continue to belong

4 Who peaceably the same long time did wield:

wield > command, govern

5 And all men's hearts in due obedience held:

due > fitting

6 Till her sisters' children, waxed strong

waxed > grown

7 Through proud ambition, against her rebelled,
8 And overcome kept in prison long,

overcome > [Cordelia, overcome,]

9 Till, weary of that wretched life, herself she hanged.

210.33

Then gan the bloudie brethren both to raine:
2 But fierce _Cundah_ gan shortly to enuie
His brother _Morgan_, prickt with proud disdaine,
4 To haue a pere in part of soueraintie,
And kindling coles of cruell enmitie,
6 Raisd warre, and him in battell ouerthrew:
Whence as he to those woodie hils did flie,
8 Which hight of him _Glamorgan_, there him slew:
Then did he raigne alone, when he none equall knew.

1 Then began the bloody brethren both to reign:
2 But fierce Cunedagius began shortly to envy

Cunedagius > (Son of Regan)
envy > resent

3 His brother Morgan, pricked with proud disdain,

brother > cousin, kinsman
Morgan > (Son of Goneril)
disdain > indignation

4 To have a peer in part of sovereignty,

peer > rival
part > [the] function, office, business; _hence:_ discharge
sovereignty > royal authority

5 And, kindling coals of cruel enmity,
6 Raised war, and him in battle overthrew:
7 Whence, as he to those woody hills did fly

fly > flee

8 (Which hight of him Glamorgan), there him slew:

hight of > were named after
Glamorgan > [Glen of Morgan]

9 Then did he reign alone, when he none equal knew.

equal > [equal to him]

210.34

His sonne +_Riuallo_+ his dead roome did supply,
2 In whose sad time bloud did from heauen raine:
Next great _Gurgustus_, then faire _C{ae}cily_
4 In constant peace their kingdomes did containe,
After whom _Lago_, and _Kinmarke_ did raine,
6 And _Gorbogud_, till farre in yeares he grew:
+Till+ his ambitious sonnes vnto them twaine,
8 Arraught the rule, and from their father drew,
Stout _Ferrex_ and sterne _Porrex_ him in prison threw.

1 _Riuallo_ > _Riuall' 1590; Rivall' 1609_
7 Till > Then _1590;_ When _1609_

1 His son Rivallo his dead room did supply,

dead room > [place created by his death (cf. 207.11:8)]
supply > fill

2 In whose sad time blood did from heaven rain:
3 Next great Gurgu