Original: Historically the county town was Abingdon , but in 1867 the town of Reading -- by then much larger -- superseded Abingdon in this role . In 1974 local government reorganisation moved Abingdon and several other north-west Berkshire towns into Oxfordshire .
Simplified: In the past , a town named Abingdon was the county town , but this town is now not in Berkshire .