Sheikh Zayed bin Khalifa Al Nahyan (1840–1909) was the grandfather of Sheikh Zayed bin Sultan, first president of the United Arab Emirates. He was born in the emirate of Abu Dhabi, in what was then called Trucial Oman, sometime around 1840. He lived much of his early life with the Bedouin of Abu Dhabi. He made Ruler of Abu Dhabi after the deposition of his cousin, Sheikh Said bin Tahnun, in 1855. He ruled for 54 years, until his death in 1909.
Early in his rule, Zayed guided Abu Dhabi through a series of conflicts with the Emirate of Sharjah. In 1868, he killed the Ruler of Sharjah, Sheikh Khalid bin Sultan, in single combat. The death of Khalid brought an end to the conflicts. The result of these fights left Abu Dhabi the most powerful Sheikhdom in the Gulf region.
Zayed also led Abu Dhabi in an extended war with Qatar in the 1880s that secured the western border of Abu Dhabi. He united with Omani forces to drive the Saudi troops from the Buraimi area in 1870. This left the forts defending the Buraimi Oasis in permanent control of Abu Dhabi and forced the Saudis to abandon their designs on Oman. Abu Dhabi's influence and control over this area steadily grew afterwards.
He was a strong leader and all tribes along his Emirates treated him with respect. The borders of the Emirate were extended three times, to reach near Qatar in the west and to touch the Rub' Al Khali in the south.
He was also a pearl diving fleet owner and a merchant that helped other people around Emirates financially and served as a wise father.
In 1892, Khalifi signed a treaty with the United Kingdom which effectively ceded control of Abu Dhabi's international commercial relations to the British.