José Aldo became the inaugural UFC featherweight champion after the WEC merger.
Before the merger, Aldo was the final WEC Featherweight Champion. When Zuffa folded the WEC featherweight division into the UFC, Aldo was promoted to the new UFC championship rather than having to win a separate title bout. The change was formally recognized at UFC 123 on November 20, 2010.
His first UFC featherweight title defense came against Mark Hominick at UFC 129 in April 2011. Aldo won by unanimous decision in front of a record-setting crowd at Toronto’s Rogers Centre. He later defended the belt against notable challengers including Kenny Florian, Chad Mendes and Frankie Edgar.
A common mix-up is treating Aldo’s first UFC title as a vacant championship won inside the Octagon. The merger transferred the established WEC division and its champion into the UFC, making Aldo the inaugural UFC titleholder by promotion.