500 BC-AD 600: The state of Lhomon (‘southern darkness’), or Monyul (‘dark land’), is thought to have existed in the area of modern-day Bhutan.
7th century AD: The Tibetan Buddhist King Srongtsen Gampo (627-49) introduced Buddhism to the region.
747: The Indian Buddhist saint Padmasambhava (revered in Bhutan as Guru Rimpoche, patron-saint of the kingdom) arrived in Bumthang (central Bhutan) from Tibet and founded the Nyingmapa school of Mahayana Buddhism.
9th century: Several small, independent monarchies appeared, each of which was ruled by a Deb (king).
late 12th century: A Lhapa school of the Kagyupa Buddhist sect was established at Paro.
13th century: The Tibetan Phajo Drugom Shigpo introduced the Drukpa sub-sect; he confronted and prevailed over the Lhapa school, and founded the first Drukpa monasteries at Phajoding and Tango, in Thimphu valley.
15th century: Drukpa Kinley, who became known as the ‘divine madman’, arrived in western Bhutan. The scholar Pema Lingpa was born in Bumthang.
17th century: The independent theocracy of Druk-yul (‘land of the thunder-dragon’, a reference to the Drukpa Buddhists and the country’s traditional name) emerged.
1616: Ngawang Namgyal, a Tibetan lama of the Drukpa sub-sect, fled to Bhutan from Tibet. Namgyal later took the title of Shabdrung (‘at whose feet one submits’) and founded a state monastic body under an elected spiritual leader, the Je Khenpo (head abbot), and a theocracy under the Desi, or Deb. A State Council (Lhengye Tshokdu) was also created.
1629: Construction of the first dzong, an administrative-temple-fortress complex, began at Simtokha.
1631: Tibetan armies invaded Bhutan but were defeated.
1651: Namgyal died; his death was kept a secret for half a century in an attempt to prevent the disintegration of the newly unified state.
18th century: A theory of triple reincarnations (of physical, oral and mental aspects) of the Shabdrung was established; anyone manifesting these aspects was considered a successor to the Shabdrung as head of state.