It eventually concluded after a military intervention by the Economic Community of West African States (ECOWAS) led to Jammeh's departure from the country.

After he refused, ECOWAS assembled a coalition of military forces from Senegal, Nigeria, and Ghana to intervene in The Gambia using special provisions in the organisation's charter.

Jammeh's term was initially scheduled to end on 19 January, and Barrow was sworn in as President of The Gambia in his country's embassy in Senegal.

Following the announcement of the results of the elections, opposition supporters widely celebrated the surprise victory and were stunned by Jammeh's concession of defeat.

"[12] A few days after the election, 19 opposition prisoners were released, including Ousainou Darboe, the leader of Barrow's United Democratic Party.

"[13] On 9 December 2016, Jammeh appeared on Gambian state television to announce that he had "decided to reject the outcome of the recent election" due to "serious and unacceptable abnormalities ... during the electoral process".

Within a year after the handing over of power in January 2017 and said "We are going to have a national commission for asset recovery" to obtain the return of money and property from Jammeh and his family.

[17][18] By 10 December, the military of the Gambia was deployed in key locations in Banjul, the capital, and set up sandbagged positions with machine guns, although they were just waving the citizenry through the checkpoints.

[19] The Guardian's African correspondent speculated that the prospect of prosecution under a new government might have led security and military leaders to back Jammeh.

[30] In his 2017 New Year address, Jammeh furiously criticized the position taken by ECOWAS, saying that "it is totally illegal as it violates the principle of non-interference in the internal affairs of member states" and "is in effect a declaration of war and an insult to our constitution".

[34] They called Jammeh's rejection of the election results "tantamount to treason" and passed a unanimous resolution calling for the resignation of the Chief Justice of the Supreme Court, Nigerian judge Emmanuel Oluwasegun Fagbenle, for gross misconduct, saying he had shown a lack of independence and impartiality by campaigning for Jammeh and inappropriately interfering with decisions made by judicial officials.

[35][34][22] The Gambia teachers' union called Jammeh's action "a recipe for chaos and disorder which undoubtedly endangers the lives of all Gambians particularly our children".

[45] It was announced that a delegation of four West African heads of state planned to go to The Gambia on 13 December to try to persuade Jammeh to accept the results of the election and step down.

[46] The African Union said it also planned to send a negotiating delegation to The Gambia, led by President of Chad and chair of the AU Idriss Déby.

"[46] On 14 December, United Nations officials said that Jammeh would not be allowed to remain head of state and would face strong sanctions if he continues to try to do so after his current term expires.

[49] Mohamed Ibn Chambas, the United Nations Special Representative for West Africa and the Sahel said "For Mr. Jammeh, the end is here and under no circumstances can he continue to be president.

"[49] Ban Ki-moon, the Secretary-General of the United Nations, said the refusal to accept the election result was an "outrageous act of disrespect of the will of the Gambian people".

[52] Despite pressure from regional leaders, Jammeh, speaking on television on the evening of 20 December, said that he would not leave office at the end of his term in January unless the Supreme Court of the Gambia upheld the results.

[62] However, Jammeh appeared on state television and declared that he will stay in office "to ensure the rule of law is upheld" until the Supreme Court makes a decision on his appeal, which is not expected until at least May 2017.

[63][64][65] On 3 January, it was reported that Alieu Momar Njai, the head of the electoral commission, had left the country or gone into hiding due to concerns about his safety.

[66][65] In a New Year message, Chief of Defence Staff Ousman Bargie affirmed that Jammeh had "the unflinching loyalty and support of The Gambia Armed Forces".

[68] In a televised declaration, Jammeh justified the move by citing "the unprecedented and extraordinary amount of foreign interference" during and preceding the December 2016 vote.

[70] The National Assembly approved the state of emergency along with a resolution denouncing foreign interference and an extension of its own term, due to end in April, by three months (to 11 July 2017).

[72] Following the announcement of the state of emergency, Senegalese troops were deployed to the Gambian border on 18 January as the spearhead of the ECOWAS military response.

[75] The opposition vowed to go ahead with the inauguration at Banjul Mini-Stadium,[76] but this was later cancelled, with Barrow's spokesman Halifa Sallah stating that he would be sworn in at an undisclosed location.

It backed ECOWAS' efforts to ensure the results of the 2016 presidential election are respected, but endorsed "political means first", without expressing support for military action.

[84] Senegal later halted its offensive in order to mediate the crisis one final time, with the invasion to proceed at noon on 20 January if Jammeh still refused to relinquish power.

[85] That night, Jammeh sacked the remainder of his cabinet, according to reports from the Gambia Radio & Television Service, and announced he would replace it with new members.

[92] During the early hours on 21 January, Jammeh announced on state television that he was stepping down from the post of president,[93][94] and he left the country later the same day.

Five days later, Barrow returned to the Gambia while requesting the ECOWAS troops (now numbering about 2,500) to stay for at least six months to help him firmly establish order.