[5][6] After years of local petitions to Trinity House, the organisation agreed for a lighthouse to be built at Portland Bill.

[8][6] Designed as leading lights to guide ships between Portland Race and the Shambles sandbank, they shone out for the first time on 29 September 1716.

[9] In 1789, Trinity House hired the Weymouth builder William Johns to demolish and rebuild the lower lighthouse.

[8][5] The new lighthouse, 63 feet high and built of Portland stone, was then installed with six Argand lights and spherical reflectors, together with a new lens system created by Thomas Rogers.

Though they only remained in place for a few years, they represent the beginning of something that would later become standard practice: the application of dioptric technology to a lighthouse.

[11] In 1869 Trinity House had both lighthouses rebuilt to allow for further improvements to be made;[8][12] at the same time they were each provided with a large (first-order) fixed optic, designed and built by James Chance.