4 SAI came into being on January 1, 1962, with the first troops arriving that April. Troops were detached on operational duty from 1969.
The unit converted to a mechanised role from 1982 and was upgraded to an operational mechanised battalion group, with an attached artillery battery and armoured squadron. From 1983, the unit used the moniker “62 Mechanised Battalion” when operationally deployed.
Troops were contributed to operations Dolfyn, Askari (14 soldiers killed in action), Alpha Centauri, Moduler (11 soldiers killed in action) and Hooper. During Hooper, 62 Mechanised also had a tank squadron from the School of Armour under command. Internal operations contributed to were Palmiet (support to police in the Gauteng region during 1984), Kharos (the same, but in the Eastern Cape in 1985), Pebble (countering guerrilla infiltration from Mozambique in 1985, 1986) as well as Windvleuel and Xenon in black townships in the now-Mpumalanga.
4SAI also supported the signing of the Nkomati accord between South Africa and Mozambique in March 1984 and took part in Exercise Thunder Chariot in September of that year. The exercise was, at the time, billed as the largest mobilisation of South African forces since World War Two.
Current role: Motorised infantry.
Current base: Middelburg, Mpumalanga