SORRY ABOUT THAT JUST REALISED THAT MY POST IS UNREADABLE - and editing it didn't work, So here it is again - hopefully it makes a bit more sense Hi - just realised that the South Lancashire Regiment is a prefect example of Infantry Battalion numbering system: In 1914/18 it was increased from 1[SUP]st[/SUP] and 2[SUP]nd[/SUP] Battalions who were all regular (full time) soldiers to which a Training batallion – 3[SUP]rd[/SUP] Battalion was added Then came the Territorial Army Battalions (composed of TA ie part timers such as the National Guard but increasingly conscripts as the War progressed) 1/4[SUP]th[/SUP] Battalion, 2/4[SUP]th[/SUP] Battalion, 3/4[SUP]th[/SUP]Battalion 1/5[SUP]th[/SUP] Battalion, 2/5[SUP]th[/SUP] Battalion, 3/5[SUP]th[/SUP]Battalion 6[SUP]th[/SUP] Battalion and all the way to 18[SUP]th[/SUP]Battalion Of course the British Army in WW1 was the vastly larger than in WW2 and most of these Battalions disappeared but would retain for example the 1/4[SUP]th[/SUP]Battalion number even if all the other 4[SUP]th[/SUP] Battalions had disappeared. By the way, I see that these were grouped at various stages into no less than 9 different Divisions. THE POINT is that for the Infantry you should look for theBattalion not the Regiment. Cavalry You live and learn – I should have given the full title to the Dragoon Guards which is 4[SUP]th[/SUP]/7[SUP]th[/SUP] Royal Dragoon Guards.So the clue to their amalgamation is the (th) in both numbers. Artillery The numbering system is a bit more logical in the RoyalArtillery. For AA (and these would be massive guns) a typical Brigade eg at Dunkirk 1[SUP]st[/SUP] Anti-Aircraft Brigade Royal Artillery was composed of: 1[SUP]st[/SUP] Anti-Aircraft Regiment 6[SUP]th [/SUP]Anti-Aircraft Regiment 85[SUP]th[/SUP] Anti-Aircraft Regiment Infantry Battalions would sometimes have an AA Platoon but this would only be a truck loaded with a couple of Bren guns. Your father So getting back to your father – I would have thought that as a WOII in the RA, he would be unlikely to be in the South Lancs, an Infantry Regiment. Also it is very unlikely that following the severe reduction in Army units after WW2, he served in the same Regiment throughout the period. You need his Army number if you can get it and you need his Service Record. It is still possible to obtain both by downloading forms from the MoD on line http://www.mod.uk/DefenceInternet/AboutDefence/WhatWeDo/Personnel/ServiceRecords/MakingARequestForInformationHeldOnThePersonnelRecordsOfDeceasedServicePersonnel.htm Its free to wives\partners but as his child you will probably need to pay £30 and be very patient – its taking them about 9 months to processreplies.