The Republic Arms 401 was originally designed as a compact pistol for the South African Police. The country was under international arms embargo, and the police wanted to replace their assortment of Beretta 81s, PPS, and PPKs with something standardized, for use by detectives and female officers. They put out a request for an all-steel gun (they were quite specific on that) like the Astra A75. Republic Arms submitted the RAP401, and it was adopted in 1990.
In 1994, the newly elected government in South Africa ended the purchasing of new firearms, including the RAP401. This left Republic Arms looking for a market, and with the end of the arms embargo they decided to see if they could succeed on the US commercial market. In addition, they realized that the RAP401, begins stronger and heavier than really necessary for 9x19mm would be an excellent candidate for the new and popular .40 S&W cartridge. So they adapter the design for .40 caliber and exported it as the RAP440 alongside the 9mm RAP401. The guns sold reasonably well in the US thanks to their low price point but good quality, and remained in production until 2006.