In the 1960s , the flooding of the Tryweryn Valley to provide the city with water soured relations with many people in Wales .
The decline of Liverpool after the Second World War and changing patterns of Welsh migration , caused the Welsh presence to diminish .
In the 1960s , the flooding of the Tryweryn Valley to provide the city with water soured relations with many people in Welsh .
The decline of Liverpool after the Second World War and changing patterns of Welsh migration , caused the Welsh presence to diminish .