Add "terminate_monitor" just before the "end_monitor" in your script 
edit: Oh, you want it to pop up every time they capture those regions?
Add a new condition to your event "and I_EvenCounter england_owns_regions 0 (just an example, you can give it any name).
Also add a new command when the event pops up "set_event_counter england_owns_regions 1"
And then add a new event, something like this:
Code:
monitor_event FactionTurnStart FactionType england
if not I_SettlementOwner any settlement you want them to own for the event to trigger = england
set_event_counter england_owns_regions 0
end_if
(Repeat the green part for every settlement you want the faction to have to trigger the event)
end_monitor
I guess someone knows a more efficient way, but this looks good IMO