During his tenure, Adenan held the position as the President of Parti Pesaka Bumiputera Bersatu (PBB), which is part of the Barisan Nasional coalition.

[11] Adenan's political career began in 1976 when he was appointed as the legal advisor and a committee member of Parti Pesaka Bumiputera Bersatu (PBB)[12] Later in 1979, he contested in elections and won twice, the first in a by-election for the Muara Tuang constituency in January, and the third Sarawak state election several months later in the same constituency.

Two years earlier, Adenan was appointed by Taib as PBB publicity chief as the former sought to purge Abdul Rahman's influence in the party.

He officially took the oath of office in a ceremony held at Astana on 28 February 2014,[13][14][15] Later that year, in conjunction with the Governor of Sarawak's 78th Birthday, he was awarded the "Datuk Patinggi" title.

He spoke openly about strengthening Sarawak's autonomy[17] and called for higher state's share of petroleum royalty, much to the consternation of Putrajaya and the national oil company Petronas.

[19] During his capacity as chief minister, he also announced that Sarawak has adopted English as the official language of the state's administration, apart from Bahasa Malaysia.

At the same time, the federal government leaders was preoccupied with various issues such as resignation of deputy prime minister Muhyiddin Yassin for protesting against 1Malaysia Development Berhad scandal, Sabah State Water Department corruption probe, and economic slowdown due to low prices of raw materials.

[21][22][23] Other leaders such as Mohamad Sabu and Azmin Ali stated that Najib had failed to check Adenan from demanding more from the federal government.

[24][25][26] Despite the regional sentiment, Adenan is opposed to the idea of secession from Malaysia as "it was the wisest decision made by Sarawak 53 years ago".