 Filming switched from the UK to Ireland after the British Ministry  of Defence declined to provide the huge numbers of soldiers to act  as extras in the film. The Irish Defence forces supplied 250 men  drawn from a mix of units of the FCA (Army Reserve) and Slua Muiri  (Navy) reserves. They spent four weeks in the surf on the beaches  while filming the landing scenes. The UK MoD also supplied a couple  of hundred soldiers from their reserves, but not the thousands which  Spielberg had asked for.