It was not until the mid-nineteenth century that the practice of free trade between the two sides of the Channel really develops.
In 1842, the English greatly reduce taxes on raw materials, manufactured and semi-manufactured products and abolish export duties on finished products.
Three years later, they act the same on all export duties and most import taxes.
In 1853, Gladstone, Chancellor of the Exchequer of Palmerston, accentuates the customs barriers.
In 1860, the Treaty of Cobden-Chevalier is signed, still taxed products were essentially luxury goods.