The story
The Company was established in 2000 when BG Group demerged its UK gas transmission business, formerly known as Transco, and named it Lattice Group.
In October 2002 Lattice Group merged with National Grid plc to form National Grid Transco.
In July 2005 National Grid Transco was renamed National Grid plc to provide 'a unifying identity across its operations'.
From Wikipedia’s article on Lattice Group, shared under CC BY-SA 4.0.3