In the 19th century, trenchwork or defensive dugouts were referred to as lines. Hence the huge complex of forts, ditches, inundations and other obstacles built by Wellington in 1809 just behind Lisbon were known as the 'Lines of Torres Vedras'.
In the 19th century, trenchwork or defensive dugouts were referred to as lines. Hence the huge complex of forts, ditches, inundations and other obstacles built by Wellington in 1809 just behind Lisbon were known as the 'Lines of Torres Vedras'.