This fort was built by Raja Rai Singhji, the sixth ruler of Bikaner, who ruled form 1571 to 1612 AD. Raja Rai Singhji could Marshal the revenues of a Kingdom increased by the conquest of half Marwar and grant of half Gujrat and made use of ample funds from Jodhpur and Western Deccan for the construction of this fort. A contemporary of Mughal Emperor Akbar and Emperor Jehangir, he held a very high rank in the Imperial court. As a reward for this services as military commander, he was granted fields of Gujrat and Burhanpur by the Emperor. During his tenure in imperial service he traveled far and wide which gave him vision and great ideas about art and architecture and we can see how meticulously these ideas were incorporated in the architectural styles of his building in Junagarh fort.