The Tower was originally built in 1809. It was one of twenty-nine Martello towers situated on the east coast of England, constructed to defend the country against the threat of invasion by Napoleon Bonaparte and his armies. In total, 103 Martello Towers were built between 1804 and 1812. Seventy-four were built between 1804 and 1808 along the Kent and Sussex coastlines from Folkestone to Seaford, and twenty-nine were constructed along the east coast between Point Clear near St Osyth and Aldeburgh from 1808 to 1812. The south coast towers were numbered 1 – 74, while the east coast towers were lettered A – Z. Three additional east coast towers are known as AA, BB and CC.