It was incorporated in 1965 by bringing together the Middlesex Municipal Boroughs of Edmonton, Enfield and Southgate.

Enfield’s Capel Manor, a glorious horticultural centre on the Middlesex/Herts border, was so annoyed at the Royal Mail for putting it postally in Hertfordshire, that it vigorously campaigned to be officially given back its Middlesex address, and won! In thanks, top Patriot, Mr Bill Bossom, cultivated the beautiful Middlesex rose