The South Eastern Railway (SER) completed its main line from London to Dover, Kent in 1844, branching off the rival London, Brighton and South Coast Railway's (LBSC) line at . Construction of a single line branch from (modern spelling "Tonbridge") to Tunbridge Wells, a fashionable town where a chalybeate spring had been discovered in 1606, began in July 1844. At the time, Parliament had not given assent for the railway. The Act of Parliament enabling the construction of the line had its first reading in the House of Commons on 28April 1845. The bill completed its passage through the House of Commons and the House of Lords on 28July, following which Royal Assent was granted on 31July by Queen Victoria.