Why are there roman numbers mentioned above each stanza of The Patriot?

Apparently, it’s Robert Browning’s own style of writing that he numbers the stanzas of his poems in many cases, as in ‘The Last Ride Together’, ‘Meeting at Night’, ‘The Laboratory’ etc. apart from our present poem ‘The Patriot’. I find no special reasoning behind it. But yes, you can always try and find one. Some would like to think that each numbered stanza reflects a chapter in the patriot’s life, though I personally don’t find much merit in that logic.

It is to illustrate the building up of the climax of the narrative monologue.