Castle located off Dame Street was founded in 12-th century by a
Cambro-Norman nobleman Meiler Fitzherny who was illegitimate son of King Henry I by Nest- daughter of Rhys ap Tewdwr, the last king of Deheubarth( South Wales).
In 1204 some time after Norman invasion of Ireland, Meiler Fitzeherny was instructed by King John of England to erect the castle of typical Norman courtyard design ( Romanesque style developed by Normans) The building was raised for administration and defensive purposes and formed a corner part of defensive city walls surrounded with moat artificially floaded with River Poddle.
Since XII -th century Dublin Castle has been a constantly developing architectural entity up to the present day.
In 1224 the castle was credited a chapel and next major redesign was made in baroque style by Surveyor General Sir William Robinson in 1688 - when he proposed
ground floor arcades and the steep dormered roofline.( simillar to his Royal Hospital Kilmainham)
Later some further additions were designed to create a lower yard for administration and in eightinth century as Georgian streetscape of Dublin was being developed, the upper yard of castle was also developed by Sir Edward Lovett Pearce using the basic design inherited from Sit William Robinson, then the erection of State Apartments followed - which can be seen from the rear side, painted in bright colours, reminding the lego blocks.
Another extensions that followed those developments were designed by Francis Johnston the main vehicular entrance called Ship street entrance,the Chapel Royal -also called Church of the Most Holly Trinity, built in XIX-th century in neo- gothic style( building adjoining the powder tower with the crenelation) , and Chester Beatty Library, and later designed by Jacob Owen carriage block in neo gothic style and neo classical carriage office.
The last extention of this incredibly complex but unite hybrid is conference centre built in 20-th century and also the modernisation of the library.