Born 1880, died 1929. The second son of Kgosi Linchwe Kgamanyane Pilane (or Linchwe I) , Isang was born in Mochudi in 1866. Together with his elder brother and heir to the Kgatla throne, Kgafela (b. 1880), Isang was educated in Setswana and English by the well-known Pilansberg teacher-evangelist, Thomas Phiri, in the border village of Sikwane. For his secondary education, Isang went on to the Anglican school, Zonnebloem College, in Cape Town. On his return, he worked briefly at the cattle post in Mochudi. In 1914, the heir, Kgafela, died unexpectedly at the age of 34 and Isang became secretary to his father, Linchwe, and carried out many of the administrative tasks pertaining to the running of the community's affairs. At the age of only 28, "Isang was already bold and confident." Realising this, his father, sent him to Moruleng (in the Pilansberg) to perform certain tasks delegated to him by his father, following the death in office of the deputy chief there, Ramono Pilane, in 1917. Travelling to Moruleng by horse, Isang settled Ramono's estate and oversaw the appointment of Dialwa as a regent (See also 'Tidimane Samuel Ramono Pilane'). A year later, again on the instruction of his father, Isang travelled to Pretoria to finalise the title deeds for all the Kgatla-owned land in the Pilansberg.
In 1920, when his father suffered a stroke and was incapacitated, Isang was appointed as regent the following year. (The sick and old Linchwe died in 1924). He was serve in this capacity until the heir, the late Kgafela's minor son, Molefi, had come age. At the regency installation ceremony in Mochudi, the ambitious Isang demanded that the elders place the leopard skin upon his shoulders as a chief, but this was rejected and the skin was placed on the kgosi's stool instead, symbolising his acting capacity.
A strong, capable and hardworking leader, acting Kgosi Isang Pilane initiated and completed a number of important development projects for the baKgatla on both sides of the border. He, for example, saw to the construction of a number of badly needed boreholes while in Mochudi, the building of 'Mochudi National School' under his leadership and supervision in 1923 was a great success. This school was attended by baKgatla pupils from both sides of the border. In the Pilansberg, Isang oversaw the construction of a "Bakgatla National School" in Moruleng in order to provide a better education for his people than that provided in the DRC schools which were seen as placing too much emphasis upon religious education at the expense of other learning. Isang also assisted the Pilansberg baKgatla in their acquisition of more land. Probably using the opportunity he had as a regent, but with all powers, duties and privileges of a chief, Isang accumulated considerable property during his regency. He, for instance, bought the farm Applikasie near Magong using resources contributed by the baKgatla, but which he then registered in his own name.
Although as a leader Isang was strong and capable, he is also reported to have had his negative side, especially in Mochudi. He is said to have been overly strict, banning the sale and consumption of liquor, for example. He is also reported to have been "crafty," "intensely jealous and quick to anger" and a "master of intrigue and a bully." Nevertheless, Isang was the most progressive kgosi of his time and a truly "remarkable man."
On 14 October 1929, at the age of 43, Isang relinquished his regency and passed on the bogosi to Molefi.