Officers Saddlery from 1856 to 1903 were the MK I, II, and III
Wood Arch S.O. patterns.
After 1903, until the end of WWI the MK III was gradually superceeded
by the MK IV. The MK IV strongly resembled a civilian hunter saddle, with fan and burrs added to the sidebars.
The MK V was an evolution of the MK IV, with the skirts broght
forward to accomodate shorter stirrups and a more forward seat.
The Mk IV transitioned
to the Mk V after WWI had ended. As late as 1932 the saddlers handbook was addressing converting Mk IV's to MK V standard,
and marking them as MK. IV*. There is very little to distinguish between them.
There was a WWI time and material saving
variation on the MK IV with canvas numnahs (detachable). It was known as the pattern '15.
The MK IV first appears in
LOC 11954, in July or August of 1903. It is important to note that it was British practice not to issue a new pattern until
the old stocks were exhausted (unless otherwise noted). Thus the Saddle Officer's Mark III (first sealed in August of 1899
(LOC 9839) would have continued for quite some time. The MK III closely resembles the Mk I and II; all had exposed wood arches
and are sometimes confused with the first Universal Pattern (wood arch) saddle from 1856.
Section IV of the
Handbook for Military Artificers - 1915 (reprint of 1918) specifies that Mark III's were for issue to officers of the R.A.,
R.E. and A.S.C.
The same book lists the Mark IV as "the latest pattern for all (other) officers".
Listed below are links to S.O. related LOC's:
