Complex sentence: In 1996, Cleveland was abolished, and Middlesbrough then became a unitary authority, geographically within North Yorkshire for ceremonial purposes only however Middlesbrough now forms part of the Tees Valley with Hartlepool, Stockton-on-Tees, Darlington and Redcar & Cleveland.
Split into simpler sentences: In 1996, Cleveland was abolished, and Middlesbrough then became a unitary authority, geographically within North Yorkshire for ceremonial purposes only. However Middlesbrough now forms part of the Tees Valley with Hartlepool, Stockton-on-Tees, Darlington and Redcar & Cleveland.