In his teachings, the Buddha retained many elements of the vedic teachings of India of his time, including the concepts of samsara and karma. However, the Buddhist differed from the vedic teachings in a sense that Buddha opposed the animal sacrifices. In addition the Buddha taught that anyone regardless of caste who followed the Eightfold Path could achieve nirvana. During his lifetime, the Buddha institutionalized his teachings by forming the sangha.  It is written that the Buddha lived till nearly eighty years and died under the sal tree in Vaishali.  It is also believed that the Lord Buddha died at the same day he was born.

Is this true?

The last sermon before he died was quoted “decay is inherent in all component things; work out your salvation with diligence!” Nelson, 148.
Do you think that one of the reasons why Buddhism flourished in Nepal was due to the Kirat king?
This was one question by my lecturer.

Deeply looking Buddhism did not survived today as in the case of India due to Hindu and Muslim rulers. Beside Kirat I understood are not Buddhist.  They have their own religion called "Mundhum" based on nature & ancestors worship or the “Indigenous religion” as the religion of the World called it.