It is well known how the village Katri Sarai came into existence, but how it was named as Katri it is not known. When Guru Nanak Dev was moving on his India tour he had camped at here along with his followers. During earlier times an inn existed here. There was a fort; situated at about 700 yards to the south of the Sarai (inn). The fort was built during the rule of Maurya Dynasty. The same of the village where there was population around the fort is Katridih. During the rule of the later rulers, army was stationed in the said fort for providing security at the Bihar-Assam Trade route. A large caravan of traders used to travel on the Bihar-Assam Trade route. Waiting place for stay of traders was situated within this Sarai (Inn). Rulers of yester years had built 3 ponds around the Sarai (Inn) for convenience of the travelers. The ponds have now shrunk and have become short in area, but still exits. Guru Nanak Dev and his followers had camped at the upper most pond, situated extreme end of North. One of Guru Nanak Dev’s disciples, Amichand had settled here, following the wishes of the Guru and he got built a building called Satsang Bhavan. For construction of Satsang Bhavan the rules of those times had given the land. Later on some villages also came up there.

During those days all problems of the people were solved in the Satsang. During sitting in the Satsang not only religious discourses were delivered, spiritual topics discussed, but the saints used to do anything in order to relieve the hapless people of their sufferings and apart from it they also used to treat the patients with herbs plants.

At present the Sangat (Gurudwara) has almost turned into ruin and there is also no religious pries (Granthi) to look after it. Manuscript of Guru Granth Sahib has also been stolen. But now a school has been built on the land of this Gurudwara where children of the poor villagers acquire primary education.

The said Amichand whose original abode existed near Madhuban (Vrindavan- Mathura) rehabilitated village at this venue. He was a married person and after his death his generations that followed him, had been treating diseases through Ayurveda.

Katri Sarai is a part of Rajgir subdivision. Rajgir is regarded as the one of the oldest monarchy and town in the world. Plenty of medicinal plants utility grew in the hills and forests of Rajgir. It was the field of the work of the ascetic, Jeevak who treated Lord Buddha and propagated his philosophy here. People in the entire Nalanda district have deep and profound faith towards Ayurvedic system of treatment. Tradition continues to perpetuate in one form or the other.

Initially Amichand’s descendants also carried on providing free treatments to the patients in the spirit of service to masses even after demise of Amichand, through herbal and Ayurvedic treatment. But, due to introduction of postal services when the Nanakshahi Sangat started receiving letters from distant places, then Granthis sought services of Basudeo Chand Barahpuria and Akhil Kishore Barahpuria whose ancestors was Amichand who were experts in Ayurveda and medicinal herbs or getting herbal medicines prepared through them and sending the same by parcels to patients. Initially this work was done free of charges. The reason being that Sangat had their own fertile agricultural land spread over thousands of acres. The patients whom medicines was sent after getting cured of their ailments used to send eight annas ( half a rupee), 1 rupee or 2 rupees through the money orders. Some of the cured patients also used to parcel the same wooden boxes in which their medicines were packed by putting gold or silver coins inside such wooden boxes. Vasudeo Chand Barahpuria and Akhil Kishore Barahpuria were landlords and they also used to treat the patients as a matter of their hobby.

Similarly a rich person from Indore, who had got relieved of leucoderma, gave an advertisement in Newspapers about these physicians where after their profession changed completely. Thereafter they gave up Zamindari and started practicing Ayurvedic treatment exclusively. Previously lot of rich patients who had been fully cured, started giving advertisement for the said both the persons, driven by the intention serving the humanity, but later on both the physicians started giving advertisement in their own names.

Vasudeo Chand Barahpuria was also appointed as a branch Post Master during the British rule. During those days there was no vacancy for the post of a Branch Post Master, rather the most famous and educated person was appointed as a Branch Post Master. Initially the late Vasudeo Chand Barahpuria had been giving advertisement under the name ‘Vaidya Vasudeo Chand’ but he was firm oppnonent of British rule and had connections with revolutionaries. Hence he had resigned from the post of Branch Post Master, as he was wanted person for the police. Then he stopped giving advertisements in his name and also stopped asking for money orders in his name. In 1934 he had started giving advertisement under the name of Shri Ayurvedic Pharmacy. After establishment Of Shri Ayurvedic Pharmacy he continued to serve the patients and also continued opposing the British Government.

Shri Ayurvedic Pharmacy was later on managed by late Vaidya Lakshmi Chand his son. Vaidya Satish Chand, present Vaidya Ganesh Shankar and Vaidya Uma Shankar his grand son respectively, continued the service and managed the Pharmacy. After in the year 2001 when Vaidya Uma Shankar became a whole time Managing Director of Indigenous Laboratories (P) Ltd. At Vaidyanathdham, Deoghar, he parted ways with Shri Ayurvedic Pharmacy. Now, Vaidya Ganesh Shankar became convener of Shri Ayurvedic Pharmacy.