Established as 1 SA Infantry Training Battalion at Oudtshoorn, (hence the ostrich feathers on the unit insignia) on 26 January 1951, the unit became part of the infantry corps with its establishment in January 1954.
In 1953, the unit consisted of a headquarters, A Coy, 1 SAI; 12 Field Battery, 4 Field Regiment (Artillery); C Squadron, 1 SSB (Armour); C Troop, 16 Field Squadron (Engineers); A Troop, 10 Armoured Brigade Signal Squadron; 60 Field Workshop;, and a supply & transport company, an attempt at all arms training.
The unit was reconstituted as 1 SA Infantry Battalion in November 1967 and moved to its current base at Tempe near Bloemfontein, in November 1973.
The unit became mechanised in 1976, and the first Ratel infantry combat vehicle course was presented by Major Roland de Vries. Full scale mechanised training commenced the next year.
By 1978, 1 SAI took part in Operation Reindeer. 1 SAI was also later involved in operations Sceptic, Protea, Daisy, Askari and Moduler.
Lt JJ du Toit and LCpl AT Rutherford were awarded Honoris Crux decorations during Sceptic and Cpl AD Burgers received the same after Protea.
Mechanised leader training at 1 SAI commenced in 1979.
Peled writes that after January 1993, 151 Battalion, formed from the Southern Sothos in the Orange Free area, was re-designated as 1 SAI.
1 SAI is equipped with Ratel 20 Infantry Fighting Vehicles, Ratel 60 mm (2.4 in) Mortar Platform Vehicles, Ratel Command Vehicles with mounted 12.7 mm (0.50 in) machine guns, Kwevoel 100 Armoured Trucks for IFV Recovery, field maintenance, fuel bunkers and water provision, Samil 50 and 100 logistics trucks, Samil 20 trucks for its organic field workshops, Casppir APCs for its forward artillery observation party, and Rinkhals Field Ambulance. 1 SAI has also used Buffel IFVs and Mambas at certain stages in its history. Ratel mounted weapons include the Denel Land Systems GI-2 20 mm (0.79 in) Quick Firing Canon (QFC) (Ratel mounted), 60 mm (2.4 in) breech-loading mortar (Ratel mounted), Browning M1919 Machine gun and the Browning M2 12.75 mm (0.502 in) Machine gun.
1 SAI is equipped with the Vektor SS77 Squad Automatic Machine gun, Fabrique Nationale 7.62 mm (0.300 in) Light Machine gun, Vektor R4 5.56 mm (0.219 in) assault rifle, 40 mm (1.6 in) Multiple Grenade Launcher (MGL), Rocket Propelled grenade launcher (RPG-7), M26 Fragmentation grenade, M4 60 mm (2.4 in) patrol mortar (PATMOR), and the Denel 99 mm (3.9 in) FT5 rocket launcher.
Under Project Hoefyster, the SANDF will eventually replace the Ratel family of vehicles with the Badger system. Nine versions are contemplated of which three are earmarked for mechanized Infantry Battalions such as 1 SAI: Command (mech infantry)
Mortar (turreted 60mm breech loading long-range mortar) ( mech infantry)
Missile (turreted Denel ZT3 Ingwe)
Section (turreted 30mm cannon) (mech infantry)
Fire Support (turreted 30mm cannon, but with more ammunition than the section vehicle)
1 Ratel 20 per section, 3 sections per platoon, 1 Ratel 60 per platoon, 3 platoons per company. 2 Ratel 12,7 per company.
In 1 SAI wil ek bly, dis die eenheid net vir my, slaggereed en kommer vry, met ons ratels veg ons ver, onder die al en suider ster 1SAI Bataljon, 1 SAI! Servire, servire,servire parati is ons lese as jy vra, 1 SAI Bataljon, 1 SAI!
From the shores of Cape Agulhas, to the Northern bushfeld trees, We will fight our countries battles, in the air, land and sea, We will fight for right and freedom, we will keep our honesty, We are proud to claim the title of the 'Mechanised Infantry'.