This is definitely one of the most bitter rivalries in England, even though the two have rarely been in the same division at the same time. In the 20’s there was a rivalry between 2 shipyards, on either side of the Thames. The Millwall, London and Surrey docks, were Millwall and the Royal docks were west Ham and it was an excuse for a tear up. The 1926 strike took things on to a whole new level when West Ham were on strike and Millwall carried on working. They were rivals before a football had been kicked between them. Both clubs originated in East London, but Millwall FC moved to the other side of the Thames (South London) in 1910.