Kanyakubj Vs Saryuparin

Saryuparin Vrahmins find their refernce in Ramayana at the time when Lord Rama recahed on the banks of Saryu river after Killing Ravan. He had done brahmhatya killing of brahmin was considered a sin. None of the Brahmins helped Lord Rama to perform rituals to get rid of the sin of killing a brahmin.All refused and some Brahmin children of Kanyakubj Brahmins took part in it and had to face the wrath of their family and the entire Brahmin society of kanyakubj Brahmins. They were disowned and made to cross the Saryu river Hence, they are called Saryuparin— saryu Ke Paar

https://www.quora.com/What-does-my-father-mean-when-he-says-that-we-are-Saryupaareen-Brahmins-of-Vatsa-Gotra-and-are-Pyaasi-Mishra