Oldham 2. Preston 11. Wigan 3. Rochdale 12. Manchester 4. Barrow-in-Furness 13. Salford 5. Blackpool 14. Bootle 6. Blackburn 15. St Helens 7. Southport 16. Liverpool 8. Bury 17. Warrington 9. Bolton By the census of 1971 the population of Lancashire (including all its associated county boroughs) had reached 5,129,416, making