| May 1944 | CO: Lt Col The Lord O'Neill |
| May 44 | North Irish Horse |
| 1/5/44 | C.M.F. Churchills disembarked at NAPLES and proceed to Bde Conc area by rail. Bde comes under command of 1st Canadian Inf Div. |
| 2/5/44 | CO admitted to hospital. Orders received for Bde to concentrate under comd 1st Canadian Corps for operational role. |
| 3/5/44 | Lt Col EV Strickland MM assumes command of the Regt from 145 RAC Regt. |
| 6 - 8 | B & C Sqns engage in field firing exercise with 2nd Canadian Inf Bde. |
| 9/5/44 | Lt JN Nicholson posted in. |
| 13/5/44 | Stuart tanks proceed to 1st Canadian Inf Div conc area at MELIZZANO. |
| 15/5/44 | Advance party and some tanks proceed to MELIZZANO. |
| 16/5/44 | Main road party departs for MELIZZANO and remainder of tanks are en-trained. Main party harbours for night at BENEVENTO, info having been received that regt is now to conc at VAIRANO. |
| 17/5/44 | Road party departs for VAIRANO but info is received en route that conc area is now MIGANO. |
| 18/5/44 | Regt is fully concentrated. 1200 – Tanks move to harbour position. 1500 – A1 Echelon proceed to harbour area. |
| 19 – 21 | Tanks in harbour awaiting orders. |
| 22/5/44 | Tanks move to conc area for operation. |
| 23/5/44 | Regt participates in full frontal attack on ADOLF HITLER LINE under comd 1st Canadian Inf Div. NIH in support of 2nd Canadian Inf Bde. 0601 – Tanks cross start line. 0740 – A Sqn having come out of wood find themselves held up by extensive minefield. On the REs have cleared a passage they are pinned down by A/Tk fire. B & C Sqns advance to first objective, PONTECORVO – ACQUINO road, in support inf infantry, but meet concentration of enemy armour and SP guns. They suffer heavy casualties but eventually eleven tanks reach the objective. 1045 – A Sqn begin to organise defensive positions in and around the wood. Position of the infantry is hazy. Major GP Russell having been wounded, Capt CM Thomas takes comd of a composite force of 11 tanks which now remain in B & C Sqns. 1200 – Composite force now on second objective, junction of PONTECORVO road and Route 6, 740234. 1245 – Composite force have to withdraw owing to very heavy mortar and shell fire, without having been able to contact infantry. On the way back they run into a tank trap and lose 7 tanks. Remaining 4 tanks are ordered to join A Sqn as a counter-attack is anticipated. 1425 – A Sqn begins to fall back to defensive positions but counter-attack does not develop. 1650 – Enemy are seen to be evacuating their positions. All our remaining tanks return to defensive positions for the night. The Regts total casualties during the action were:-
| Officers- | 4 killed and 9 wounded. |
| ORs- | 29 killed and 33 wounded. |
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| 25/5/44 | Special Order of the Day issued by 8th Army Command offering congratulations on the action. Comd 1st Cdn Inf Div requests permission for all ranks of 25th Tank Bde to wear the Maple Leaf as a mark of the appreciation of his Div for their co-operation. |
| 26/5/44 | Personnel killed on the 23rd were buried in the 2nd Cdn Inf Bde Group Cemetery. |
| 29/5/44 | Orders received for the Regt to be at one hours notice to move, as from 1200 30th May, for further operations. |
| 30/5/44 | Tanks and A1Echelon leave for new area. The Regt is put on new establishment of two Churchill and two Sherman troops per Sqn, pending arrival of 75mm Churchills. |
| 31/5/44 | The establishment will become elastic in that one troop of Shermans will be replaced by Churchills as they become available from workshops. Personnel are in no way altered despite the loss of one troop per Sqn but surplus personnel will now be held by FDS. Officer establishment remains unchanged. |