The palace you see at Mysore is probably the third or the fourth generation of the palatial structure built over this location by the ruling dynasty.
Many reasons , including the shift in power and other catastrophes caused the destruction of older citadels.
The one thing that probably remained unchanged throughout the citadel's history is probably it name - Mysore Palace.
Originally this area was a bastion. A fortified area with ditches all around as in any military architecture.
Even today it is, though the dominating palace structure steals the show. You can see the fort walls, and some remains of the ditches on either sides of the main gateway (Jayamathanda Gateway) to the east of the palace compound.
The original fort was made in as early as 1574 CE. The construction of the fort is often attributed to Chamaraja Wodayar IV, the then ruler of Mysore.
What this fortification enclosed was a large community, mostly associated with the palace and the court.
The first definite mention of a palace structure is found in the text of Shrimanmaharaja's Vamshaavali ( History of the Mysore Royal Family ). The historic document says of the destruction of the then Mysore Palace by a lightning and reconstruction of a new palace by the ruling king Ranadheera Kantheerava Narasaraja Wodeyar in the year 1638.
A century later power shifted to Hyder Ali and his famous son Tippu Sulthan. That is roughly during the period from 1760 to 1799 CE.
That was a period of great turmoil in Mysore as Tipu was challenging the expansive ambitions of the British East India Company.
Tipu Sultan demolished the structures inside the palace to give way to his new capital - Nazarabad. New fortifications were built . Mysore became the City of Nazarabad. However the temples were left as it is.
In 1799 Tipu Sultan was killed in the storming of the Srirangapatna by the English forces ( Battle of Seringapatam ). That brought an end to the 4th Anglo-Mysore War. Tipu's fall practically marked the fall of the last king in India who challenged the British power.
The Wodeyar kings were re installed again as the rules of Mysore, under the British patronage.
The capital of Mysore kingdom was moved back to the Mysore city. The 4 year old Krishna Raja Wodeyar III, son of the last Wodeyar king Khasa Chamaraja Wodeyar VIII, was enthroned as the King of Mysore. From now onward Mysore became a subsidiary of the British Raj.
However there was no palace worth its name in Mysore. The enthronement ceremony happened in a makeshift venue ( shamiyana / pandal ).
The fortifications Tipu Sultan built around Nazarabad was brought down. The stones were used to build the fort around the present day palace. Inside the fort a new palace was built by 1803. That is on the same location of the palace you see presently.
In a 1897 again disaster struck. A fire broke out during the wedding ceremony of Princess Jayalakshmanni. That was a goof-up by some servant. The wooden place built in Hindu style as completely destroyed. The only remaining thing of this wooden palace was a photograph taken by a lancer in the then Mysore Army. A model of this palace is the first exhibit you see as a visitor to the new palace.
The same year the construction of a new palace was inaugurated. The then regent Vani Vilas Sannidhana, queen of Chamaraja Wodeyar X, commissioned the British architect, Henry Irwin.
By 1912 construction of the new palace was completed. The architecture of Mysore palace is unique in many ways. It is a hybrid style known as the Indo-Sarsanic , combining many architectural styles.
Later, by 1940 a few more additions were added to the palace by Krishnaraja Wodeyar IV. He is credited with the construction of many royal structures in Mysore (see the 7 palaces of Mysore).
The Durbar Hall in the front of the palace extended and the towers on either sided added (the ones with pink colored domes).
Presently the palace is in the administrative control of the government body called Mysore Palace Board.
The residence of the late Srikanta Datta Narsimharaja Wadiyar (1974-2013), the scion of the Wodayar dynasty is inside this palace campus. The old residential part of the palace also is converted into a Residential Museum.
Photograph of the Old Palace at Mysore, taken by William Henry Pigou around 1855. This palace was was destroyed in a fire in 1897. Note the massive wooden columns of the porch. A large part of this palace was made of wood, causing the damage complete in that fire accident.