James Brooke, the first White Rajah sailed from England in Dec of 1838, on The Royalist, which was a ship registered with the Royal Yacht Squadron.

During this ceremony "A new flag, which the Rajah had brought from England, was then unfurled for the first time – displaying a black and red cross on a yellow field.

James wrote "...I beg to acquaint your Lordship, that on my return to Sarawak, feeling how desirable such a measure would be, I hoisted a flag, and recommended its adoption by all native prahus and other vessels belonging to this country.

W. J. Chater stated that there were no other mentions of the colour of the cross on the flag before 1870, but in fact there are several: By the advice of others in the early 1870s, Charles Brooke, the second White Rajah, "authorised a distinction mark in the Government flag by the introduction of the crown"[18] The Eastern Crown is a heraldic symbol used by Royal Peers who have distinguished themselves in the East.

This flag was registered with the College of Arms in London and is described as "a yellow forked flag, charged with a cross per pale sable and gules charged with a crown and with the red lateral arm of the cross extended saltirewise to each point of the fork.

On 31 August 1988, the flag was replaced again with the current version along with yet another new state anthem and motto, Ibu Pertiwiku ("My Motherland") and Bersatu, Berusaha, Berbakti ("United, Striving, Serving").

It brought back the same colour scheme of the flag of the former kingdom, in a new form: the cross was replaced with two diagonal bars and the crown was substituted with a nine-pointed star symbolising the original nine divisions of Sarawak,[23] in order to eliminate any overt references to Christianity and a sovereign monarchy.

[26] The nine-pointed star serves to represent the then nine divisions in the state, whilst the colour yellow denotes the importance of upholding the law, unity and stability in diversity.

[27] The red portrays courage and black is the symbol of the abundant natural resources that Sarawak possesses.