Al Nahyan
189 days
https://en.m.wikipedia.org/wiki/Khaled_bin_Mohamed_Al_Nahyan
Mohamed bin Zayed Al Nahyan
Hereditary and elective (presumably Khaled bin Mohamed Al Nahyan)
Mohamed is the third son of Sheikh Zayed bin Sultan Al Nahyan, who was the first president of the UAE and the ruler of Abu Dhabi. Zayed died in November 2004 and was succeeded in his posts by his eldest son, Mohamed's half-brother Sheikh Khalifa bin Zayed. When Khalifa suffered a stroke in January 2014, Mohamed became the de facto ruler of Abu Dhabi, controlling almost every aspect of UAE policymaking.He was entrusted with most day-to-day decision-making of the emirate of Abu Dhabi as the crown prince of Abu Dhabi.[4] Academics have characterized Mohamed as the strongman leader of an authoritarian regime. In 2019, The New York Times named him as the most powerful Arab ruler and one of the most powerful men on Earth. He was also named as one of the 100 Most Influential People of 2019 by Time. After the death of Sheikh Khalifa on 13 May 2022, Mohamed became the ruler of Abu Dhabi; he was elected to the presidency of the United Arab Emirates the next day.
Salama bint Hamdan Al Nahyan
https://en.m.wikipedia.org/wiki/Salama_bint_Hamdan_Al_Nahyan