The building of the Lines
There were three primary lines north of the Tagus. The first line was originally intended to consist of a number of strong points to delay the French advance, the main fortifications being at Torres Vedras and Sobral. This was later converted into a full defensive line stretching from the Atlantic to the Tagus.
The second line was intially planned to be the main defensive line, but was never attacked as the French were stopped by the first line.
The third line was built to protect the embarcation point at St Julian.
Later, a fourth line was constructed to the south of the Tagus to stop any French attempt to disturb the maritime traffic on the Tagus.
The works were built by Portuguese civilians under the control of British, Portuguese and German engineers. Work continued on extending and repairing the Lines through to 1814.
The second line was intially planned to be the main defensive line, but was never attacked as the French were stopped by the first line.
The third line was built to protect the embarcation point at St Julian.
Later, a fourth line was constructed to the south of the Tagus to stop any French attempt to disturb the maritime traffic on the Tagus.
The works were built by Portuguese civilians under the control of British, Portuguese and German engineers. Work continued on extending and repairing the Lines through to 1814.