The firm Bates & Mountain was formed by the amalgamation of two other firms in 1896 making it one of the longest established legal practices in the area.

In the 19th century, Grimsby grew from a small town with a population of approximately 3000 inhabitants centred around the Old Market Place to a prosperous port with a rapidly increasing population and a thriving business community. The introduction of the railway to Grimsby and Cleethorpes was probably the largest single factor contributing towards this expansion and prosperity which continued in the 20th century.

Anderson Bates and Thomas Mountain were two of the founding partners of Bates & Mountain and were actively involved in the affairs of Grimsby and Cleethorpes.

Anderson Bates was closely connected with the Borough of Grimsby all of his life and his ancestors can be traced back in town records to 1597. He was first engaged as an office boy to William Daubney, a solicitor in the town, and eventually became a partner in the firm of Daubney and Bates. During his professional life he held many positions including Clerk to the County Magistrates, Secretary to the Permanent Building Society and Solicitor to the Grimsby Gas Board. He was closely associated with education in the area, a keen local historian and freemason.

It was as a Freeman of Grimsby and a member of the Pastures Committee that in 1849 he was involved in agreeing the route of the railway link between Grimsby and Cleethorpes. Upon his death he was described as ‘one of the most prominent of Grimsby’s townsmen’.

Thomas Mountain came to live in Grimsby as a child. He qualified as a solicitor in 1866, joining Robert Stephenson (a local solicitor) as a partner in 1874. The firm was renamed Stephenson & Mountain and in May of that year, purchased office premises at 37 Bethlehem Street, where the firm remained until October 2009.

During his professional life he held many appointments but most notably was Coroner for the Borough of Grimsby (from 1895) and Clerk to the Justices for Grimsby (from 1898 – 1929). He also represented the Board of Trade for many years and it was his proud boast that during that time they never lost a case. He was also Under-Sheriff of Lincolnshire in 1909 and on his death in 1934 at a special meeting of the Council, the Mayor of Grimsby reported his sad loss and the Town Council passed a resolution of sympathy.

On the 1st July 1896, following the death of William Daubney and the retirement of Robert Stephenson, the firms of Daubney & Bates and Stephenson & Mountain (latterly Mountain & Mountain) amalgamated to form Bates & Mountain.

There have been three generations of the Mountain family involved with the firm – Thomas Mountain’s brother, son and grandson were all partners. John Letten Mountain, Thomas’ grandson, was a partner with the firm from 1939 until his retirement in 1988.

On the 30th October 2009 the firm moved from 37 Bethlehem Street to the Old Courthouse in Brighowgate.