sad > heavy assay > assault

3 In which himself was charged heavily 4 Of hardy Nennius, whom he yet did slay,

Of > By yet > nonetheless

5 But lost his sword, yet to be seen this day.

to be seen > (HRB 4.4 records that Caesar's sword was buried with Nennius)

6 Thenceforth this land was tributary made

tributary > {Subject to imposts, paying tribute}

7 To ambitious Rome, and did their rule obey, 8 Till Arthur all that reckoning defrayed; 9 Yet oft the Briton kings against them strongly swayed.

210.50

Next him Tenantius raigned, then Kimbeline,
2 What time th'eternall Lord in fleshly slime
Enwombed was, from wretched Adams line
4 To purge away the guilt of sinfull crime:
O ioyous memorie of happy time,
6 That heauenly grace so plenteously displayd;
(O too high ditty for my simple rime.)
8 Soone after this the Romanes him +warrayd+;
For that their tribute he refusd to let be payd.