sentences:  On 1 April 1995, the Borough of Slough expanded slightly into Buckinghamshire and Surrey, to take in Colnbrook and Poyle, which received a joint parish council.Slough became a unitary authority on 1 April 1998, with the abolition of Berkshire County Council and the 1973-1998 Borough.The present unitary authority was created a Borough by the town's third Royal charter.