A Local Health Board (LHB) is an administrative unit within the National Health Service in Wales. LHBs were first established in Wales in 2003. They were 22 in number, being coterminous with the 22 Welsh local authorities. The LHBs were subsidiary to a system of NHS Trusts. This was found to be an unnecessarily complex structure. Simplification began by the merging of the Trusts, eventually reducing the number to 7 by October 2009, at which time a major reorganisation was implemented. Note that the name 'Trust' has been adopted/retained by three 'all-Wales' units within NHS Wales.