The Second World War prevented further travels until 1947, when Pallis and Richard Nicholson were able to visit the Tibetan heartland before the coming Chinese invasion. They traveled widely throughout Tibet's Tsang province, seeking to fulfill their shared desire to “absorb the spirit of the Tradition by direct experience”. Over the course of their stay they were able to make contact with each of the four major schools of Tibetan Buddhism (Gelugpa, Nyingmapa, Kagyudpa, and Sakyapa), visiting such holy sites as the ancient Pel Sakya monastery, seat of the Sakyapa and “a treasure-house of all the arts at their very best”, as well as the Tashilhunpo monastery, seat of the Panchen Lama and one of the four great monasteries of the Gelugpa.