Hello! Chanakya was the prime minister of Emperor Chandragupta, the first ruler of the Mauryan Empire. As a Brahmin statesman, he was well known for his role in Chandragupta's defeat of the Nanda dynasty.
Chanakya was a respected scholar: in fact, he was a professor of political science at the University of Takshila. He was an expert in economics, warfare, and politics. The Maghada kingdom, which ruled over much of Northern India at the time, was controlled by the Nanda dynasty. According to both Buddhist and Sanskrit texts, it was said that Chanakya was interested in a position at a daankendra or charity center. Apparently, King Dhana Nanda wanted a Brahmin to run this center. Chanakya decided to apply for the position because of his curiosity. After all, King Dhana Nanda was not known for his generosity; his avarice was well documented. It turned out that the king was just engaging in some pertinent damage control regarding his reputation: it was rumored that a plot to kill him was already underway, and King Nanda was desperately bent on repairing his poor image among the locals.
It was said that when Chanakya entered the royal palace to apply for the position, he saw nine seats lined up on either side of the throne. Eight were for the Nanda princes, and it was said that the ninth was for the new manager of the daankendra.Chanakya, never one to shy away from attention, promptly sat down on the ninth seat. When King Nanda was summoned to confront the usurper, Chanakya coolly informed the king that he was the best man for the job. After all, he was a Brahmin, well-versed in the Veda texts. What did it matter whether his upper body was caked with mud and his top knot unkempt and dirty?
King Nanda, however, saw things in a different light. He insulted Chanakya by calling him an ugly Brahmin. Some legends have the Nanda princes also insulting Chanakya, by calling him an ugly monkey. All the texts agree that the insult concentrated on Chanakya's lack of good looks. Some say that King Nanda also found Chanakya's manners wanting; interestingly, both men also thought the other arrogant. With great anger, Chanakya vowed that he would not re-tie his Brahmin topknot until he had driven King Nanda out of power and destroyed his whole clan.
I hope this helps. Thanks for the question!