[2] Under Tahnun, Abu Dhabi became a Trucial State in 1820, eventually becoming the capital of the United Arab Emirates (UAE).
However, in an 1824 peace agreement with Sultan bin Saqr Al Qasimi of Sharjah over the forts at Buraimi Oasis, it was Tahnun who signed.
[3] The exiled Sheikh Muhammad bin Shakhbut returned to Abu Dhabi in late 1823, together with a force of Manasir Bedouin and sacked the town.
Tahnun commanded the loyalty of many of the Bedouin families in the area ('You will be aware that Dhahirah belongs to us' he told the British in 1839[when?])
and established his primacy there when, in 1824, an agreement was forced on Sharjah in which Sultan bin Saqr recognised Tahnun's claim to Buraimi and then demolished the forts he had built there.