The first version of this train was inaugurated on 26 October 1996 as Guwahati Rajdhani Express which ran via Barauni. It was flagged off by Ram Vilas Paswan (former Minister of Railways) which runs as a weekly service.[1] The frequency was later increased to tri-weekly in 1997.[2]
Later, on 11 January 1999, the Second set of Guwahati Rajdhani Express was inaugurated which runs through Chhapra. It was flagged off by Nitish Kumar (former Minister of Railways) which runs as a bi-weekly service.
After that, on 24 March 2010, the third set of Guwahati Rajdhani Express was inaugurated which runs through Muzaffarpur. It was flagged off by Mamata Banerjee (former Minister of Railways) which runs as a weekly service.[3]
Later due to public demand in 2012, The three sets of Rajdhani was extended up to Dibrugarh and runs as Dibrugarh Rajdhani Express and also the frequency of First Set was increased to daily service.[4][5]
February 2021: 20503/04 Dibrugarh Rajdhani frequency increased to 5 days a week from Weekly.
On 25 June 2014, this train derailed in Chhapra, Bihar, killing four people and seriously injuring eight.[6] Sabotage by Naxalites was considered but ruled out as the cause of the crash.[7] Also, on 6 December 2016 derailed in Allipurduar district of west Bengal.