 Between 10 and 13 August the division concentrated on Salisbury Plain and began war training.On the outbreak of war, TF units were invited to volunteer for Overseas Service and on 15 August the War Office issued instructions to separate those men who had signed up for Home Service only, and form these into reserve units.On 31 August, the formation of a reserve or 2nd Line unit was authorised for each 1st Line unit where 60 per cent or more of the men had volunteered for Overseas Service.