Frederick IV of Saxe-Gotha vs Khalifa bin Zayed Al Nahyan

Frederick IV succeeded his brother Augustus as Duke of Saxe-Gotha-Altenburg. His reign was brief and uneventful, lasting only three years.

Frederick IV died without issue, ending the House of Saxe-Gotha-Altenburg. The duchy was divided among other Ernestine lines, marking the end of a 250-year-old dynasty.

Khalifa bin Zayed Al Nahyan became the Ruler of Abu Dhabi on November 3, 2004, following the death of his father, Zayed bin Sultan Al Nahyan. He also became the President of the United Arab Emirates.

Khalifa bin Zayed initiated the Masdar City project, a planned sustainable urban development in Abu Dhabi. The city aimed to be a hub for clean technology and renewable energy, including the Masdar Institute of Science and Technology.

Khalifa bin Zayed launched the Abu Dhabi Economic Vision 2030, a long-term plan to diversify the emirate's economy away from oil, focusing on knowledge-based industries, tourism, and infrastructure. The plan guided major investments in renewable energy and technology.

Under Khalifa bin Zayed's leadership, the UAE joined the Saudi-led military intervention in Yemen in March 2015, aiming to restore the internationally recognized government. The UAE deployed troops and conducted airstrikes, with significant impact on the conflict.

Khalifa bin Zayed approved the Abraham Accords in September 2020, normalizing diplomatic relations between the UAE and Israel. The agreement, brokered by the United States, established trade, tourism, and security cooperation.