Short answers, pulled from the story.
Construction of the present Potala Palace began in 1645 at the order of the Fifth Dalai Lama, Ngawang Lozang Gyatso. The external structure was completed in three years, but the full interior took 45 years to finish, with work continuing until 1694, twelve years after the Fifth Dalai Lama's death.
The palace is named after Mount Potalaka, regarded in Buddhist tradition as the mythical abode of the bodhisattva Avalokitesvara. The name derives from a sacred hill on Cape Comorin at the southern tip of India, a rocky point associated with Avalokitesvara, the bodhisattva of compassion.
Potala Palace rises 119 metres above Marpo Ri (Red Mountain) and more than 300 metres above the valley floor. The 13-story complex contains more than 1,000 rooms, 10,000 shrines, and roughly 200,000 statues.
The palace was protected during the Cultural Revolution in 1966 through the personal intervention of Zhou Enlai, then Premier of the People's Republic of China. Despite that protection, Tibetan historian Tsering Woeser has documented that the palace, which held over 100,000 volumes of scriptures and historical documents, was almost robbed empty.
Potala Palace was inscribed on the UNESCO World Heritage List in 1994. UNESCO subsequently raised concerns about modern construction near the palace and about restoration materials, prompting the Chinese government to ban buildings taller than 21 metres in the surrounding area.
From the 1st of May 2003, the daily visitor quota was set at 1,600 with opening hours of six hours. After the Qingzang railway opened into Lhasa on the 1st of July 2006, the quota was raised to 2,300 to accommodate a 30% increase in visitorship, but that limit is often reached by mid-morning.