The enclosed compound of the Narayanhity Palace Museum is in the north-central part of Kathmandu. "Narayanhity" comes from Narayana, a form of the Hindu god Lord Vishnu, and Hiti, meaning "water spout" (Vishnu's temple is located opposite the palace, and the water spout is located east of the main entrance to the precinct). Narayanhity was a new palace, in front of the old palace built in 1915, and was built in 1970 in the form of a contemporary Pagoda. It was built on the occasion of the marriage of King Birenda Bir Bikram Shah, then heir apparent to the throne. The southern gate of the palace is at the crossing of Prithvipath and Darbar Marg roads. The palace area covers (30 hectares (74 acres)) and is fully secured with gates on all sides. This palace was the scene of the Nepali royal massacre. After the fall of the monarchy, it was converted to a museum.

Answer this question, if possible (if impossible, reply "unanswerable"): Whose marriage led to the construction of Narayanhity?
Birenda Bir Bikram Shah