Lord Swaminarayan knew that the Sampraday would be too great a task for one man to look after, so he split the sampraday geographically. A demarcation line was drawn between Calcutta and Dwarika. North of this boundary known as the Uttar desh (North diocese - NarNarayan Dev), and south of the boundary became Dakshin desh (South Diocese - LaxmiNarayan Dev).
Ahmedabad became the centre of the Uttar desh and was named NarNarayan Dev Gadi. Vadtal became the centre of the Dakshin desh and was named LaxmiNarayan Dev Gadi.
Lord Swaminarayan instilled two leaders, Acharyas, to head these respective Gadi's. He decided to choose heads from within His own family, as His father, DharmaDev was well respected throughout the Sampraday. Lord Swaminarayan had two brothers and he chose one of their sons as the Acharyas.
Ayodhyaprasad, son of Rampratapji, Lord Swaminarayan's elder brother, became the first Acharya of the NarNarayan Gadi. Raghuvir, son of Iccharam, Lord Swaminarayan's younger brother, became the first Acharya of the LamxiNarayan Gadi.
Lord Swaminarayan, with other great saints decided only a householder was suitable for the position of Acharya. Since, by the nature of the role of
Acharya, he would be in contact with wealth, women and material issues on many occasions and therefore saints would not be suitable for this role.
Lord left clear instructions for the Acharyas and their predecessors. When lord left this earth to take up eternal residence in Akshardham, He left the responsibility of the satsang in the hands of the Acharyas.
A true Swaminarayan Sampraday, is one which is under the control of one of the two Acharayas.