pluperfect? of exercer?

[Katerina James]

Those that fluorished in Transcaucasia and  in Central Asia, however, excercised merely a peripheral influence on Russian history, the areas themselves becoming parts of the Russian state only in the nineteenth century.

Ceux que fluorished en Transcaucasie et dans l'Asie Centrale, pourtant, avait excuse  simplement une influence périphérique sur l'histoire russe, les régions eux-mêmes devenant des parties de l'état russe seulement au dix-neuvième siècle.

[Neil Coffey]

Nearly! -- a few points to think about:

- be careful of "qui" and "que"

- you might want to consider using the imperfect for at least the first verb (N.B. the imperfect form of "fleurir" isn't necessarily obvious :), but you could also use "prospérer")

- I think you could use either imperfect or pluperfect of "exercer" here -- just be careful of the spelling whichever you use

- don't forget the construction "ne ... que" -- you could use this for one of your "merely"/"only" (but not both, to avoid repeititon)

- careful of gender of "régions"

[Katerina James]

Ceux que prosperaient en Transcaucasie et dans l'Asie Centrale, pourtant, avait exerce  simplement une influence périphérique sur l'histoire russe, les régions eux-mêmes devenant des parties de l'état russe seulement au dix-neuvième siècle.