he taller one is the original constructed and erected on orders of Rama I on April 1782 some 15 days after his coronation and commencement of work on construction of the new City of Bangkok.
The pillar symbolized the position of the new capital and contained a horoscope intended to ensure prosperity and success from future Burmese invasions. The shorter pillar was erected 71 years later under the reign of Rama IV.
The taller pillar of Rama I symbolized a position and housed a horoscope. In Rattanakosin periods the reference to Phra Lak Muang and other city guardian spirits appears in royal incantations. As a symbol of the Chakri Siam Empire other City pillars were also erected in strategic City centers away from Bangkok but demarcation of the extent of the Empire, such as at Songkhla in the South which oversaw the Malay vassal kingdoms, in Cambodia at Battambabg, Chanthathuri and Chachoengsao, Samut Prakan and elsewhere.