Incas developed a system of accounting, where from a series of chords and with knots of different color a various thickness they kept exact records of different transactions.
Origin of Inca
Still nobodies know where the Incas had come from, or how long they had been around. There were many legends on which to base rough guesses.
Atahualpa was the Inca Empire when the Spaniards reached Inca land. HE had a civil war with his brother Huascar for the throne. It is known that Atahualpa just got the news of murder of his brother and landing of Spaniard at almost the same time. So though he just became the Emperor, he could not enjoy his Emperorship at all.
Very soon he went to visit Spanish camp at Cajamarca and was captured by Spaniards. He was asked ransom for his life, which was supplied to Spaniard. But still Atahualpa was murdered by Spaniard. With his death sovereign Inca Empire came to an end.