Five years ago, St Jerome's in Llangwm was in urgent need of repair with damp and bits of render falling down.
But a research project creating a 5m-long (16ft) tapestry illustrating the town's 900-year-old links has raised more than Â£431,000 to renovate it.
Pam Hunt, project leader, said it was a "fascinating story".
The Talking Tapestry of Langum (one of Llangwm's historical names) - which has a downloadable smart phone app to tell the story of the village's ties - forms part of the Heritage Llangwm project.
As part of the project some of the village's men had their DNA tested and found a direct link to the Flemish founders.
Norman Roach, 82 had his DNA tested and was "astounded" to discover he was directly related to the 12th Century settlers.
"To take all that in was mindboggling," he added.
After about 2,000 hours of work, volunteers in the village will celebrate the end of the history project on Saturday by putting the final stitches in the tapestry.
The Talking Tapestry of Langum will be officially unveiled by the Flemish government's representative in the UK, Nic van der Marliere. The Flemish Parliament and the Flemish Government are responsible for the legislative powers of the Flemish Community in Belgium and in Brussels.
Ms Hunt said the research project, which won Â£340,000 from the Heritage Lottery Fund, grants from CADW and other bodies, had helped save the church which was in "desperate need of work".
She said: "There's interest down here, but the whole of Wales knows so little about it."
A village in Pembrokeshire has saved its crumbling Medieval church from closure - by enlisting the help of its Flemish founders.