AHC: Roman and 'British' Empire Co-Exist

Obviously it can not be the same British Empire as OTL due to the butterfly effect of a surviving Western Roman Empire. Rather I ask that you imagine a British-Isles based maritime empire co-existing with Rome. The Requirements are as follows:

1. No POD earlier than 27 BC.

2. The period of coexistence may occur at the latest in 1800.

3. At the time of their coexistence the Roman Empire must be pagan and Latin-speaking. So no POD later than Constantine.

4. Rome must control at least Italy, Greece, the Iberian Peninsula, and a significant part of Gaul.

5. The 'British Empire' must have an advanced and large navy capable of regular trans-atlantic crossings.

6. The 'British Empire' must hold a majority of its territory outside of Europe.

Bonus Points if Britain speaks a Germanic language.

More Bonus Points if they control Australia.
 
France wins Revolutionary Wars (with or without Napoleon), takes out Ottomans while they’re at it, maintains the Cult of Reason as their official religion, and Britain accepts peace with them.

The Cult of Reason is just Enlightenment-era paganism, and French is just badly pronounced Latin, while English is pretty definitely Germanic.
 
Try avoid crisis of 3rd century. Perhaps no emperorship of Commodus. Rome suffer some instablaness but manage to survive. In some point history Germanic tribes succesfully invade Britannia and manage revolt against Rome (perhaps it suffers massive civil war). Roman empire remain pagan and is able to keep Greece or then re-conquer that later. Meanwhile Germanic tribes found several kingdoms which unify as Kingdom of Britannia. Later it becomes world power.
 
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