This poem by Thomas Wyatt is about Anne Boleyn’s execution which Wyatt is said to have witnessed from his prison cell in the Bell Tower.

V. Innocentia Veritas Viat Fides Circumdederunt me inimici mei

Who list his wealth and ease retain,
Himself let him unknown contain.
Press not too fast in at that gate
Where the return stands by disdain,
For sure, circa Regna tonat.

The high mountains are blasted oft
When the low valley is mild and soft.
Fortune with Health stands at debate.
The fall is grievous from aloft.
And sure, circa Regna tonat.

These bloody days have broken my heart.
My lust, my youth did them depart,
And blind desire of estate.
Who hastes to climb seeks to revert.
Of truth, circa Regna tonat.

The Bell Tower showed me such sight
That in my head sticks day and night.
There did I learn out of a grate,
For all favour, glory, or might,
That yet circa Regna tonat.

By proof, I say, there did I learn:
Wit helpeth not defence too yerne,
Of innocency to plead or prate.
Bear low, therefore, give God the stern,
For sure, circa Regna tonat.

By Thomas Wyatt

circa Regna tonat” means “it thunders through the realms”.