In the long-drawn political drama, Governor J P Rajkhowa was dismissed on September 22. Observers say this was apparently because he had failed to "ensure a lasting BJP-led or BJP-blessed government" in the state.
Dasanglu Pul, the third wife of former chief minister Kalikho Pul won the November 19 bye-election to Hayuliang constituency on a BJP ticket. The bypoll was held following the death of Kalikho Pul. He was found hanging inside the chief minister's official bungalow on August 9, which he was yet to vacate.
A power scam amounting to Rs 450 crore also surfaced in the state in which allegations of corruption were levelled against Union Minister of State for Home Affairs Kiren Rijiju.
Opposition Congress demanded ouster of Rijiju from the union council of ministers and a CBI probe even as the BJP leader denied the allegations.
Tragedy in form of landslides and accidents also struck the state during the year claiming over 30 lives.
The political crisis in the frontier state stemmed from the ouster of Pul from the Council of Ministers in April 2015.
Soon after his exit, Pul went about spilling the beans on the poor financial health of the state under the then Chief Minister Nabam Tuki's leadership.
Pul was also terminated from Congress though he managed to get a stay on the same from the courts. Soon some more legislators from the total 47 Congress members joined him in demanding a change in leadership.
The crisis deepened after President Pranab Mukherjee on January 26 gave his approval to the cabinet's recommendation for the state to be put under President's rule.
On January 5, the Gauhati High Court stayed disqualification of 14 Congress MLAs while on January 6,the Supreme Court agreed to hear plea of the Arunachal Speaker, removed by rebel MLAs.
The apex court on January 13 ordered not to hold any proceedings in the Assembly till January 18 while referring the issue to a Constitution Bench the next day. The Supreme Court on January 15 started examining constitutional scope of discretionary powers of the Governor.
On February 18, the apex court satisfied with Gauhati High Court's order staying disqualification of 14 MLAs, paved way for new government in the state.
The court rejected Congress' plea for floor test in the assembly on February 19, the day when President rule was lifted from the state.
Pul was sworn in as the chief minister of the state on February 20.
In a sudden turn of events, the Supreme Court on July 13 while terming Governor's decision as 'unconstitutional' ordered restoration of Tuki-led Congress government in the state. .