The story
The bank was incorporated in January 1957 by an Amiri decree in the Kingdom of Bahrain. NBB states that it was established as Bahrain's first locally owned bank.
In January 2020, NBB announced the successful completion of its offer to acquire up to 100% of the issued ordinary shares of Bahrain Islamic Bank, increasing its holding to 78.8% from a pre-transaction stake of 29.06%.
From Wikipedia’s article on National Bank of Bahrain, shared under CC BY-SA 4.0.5