The Trongsa Dzong was founded by Pal Ngagi Wangchuk as the monastery as prophesied by Palden Lhamo, the guardian deity of Bhutan. Later it became the seat of Choetse Penlop after the appointment of Chhogyal Minjure Tenpa as the first Choetse penlop by Zhabdrung Ngawang Namgyal in 1647.
In 1646, fifty two years old Ngawang Namgyel has succeeded in unifying the western Bhutan under his theocratic rule. He felt that the Trongsa by virtue of being in strategic location would play crucial role in bringing centre and eastern Bhutanmunder theocratic rule and the in the process unifying the whole country.
Zhabdrung found ideal person in Chogyal Minjur Tenpa who had unquestionable loyalty and integrity who could bring feudal lords of Sharcho Khorlo Tsipgay under rule of Zhabdrung. Taking the unification of eastern Bhutan as good omen, Minjure Tenpa built the so-called Druk Minjure Choekhor Rabten Tse Dzong in 1644 as commanded by Zhadrung Ngawang Namgyel.
The structures and extra buildings to the Dzong was added by subsequent governors and in 1853, even Jigme Namgyel built Dechog Lhakhang. Now the Dzong was total of 25 Lhakhangs. Durung the initial period, the governors were known as Choetse Chila as they were monks until replaced by non-monk chiefs later.
In 1853, Trongsa Penlop Tshokey Dorji resigned paving way to Jigme Namgyal who later became most powerful leader in the kingdom and whose son became first hereditary king of Bhutan. Even before Jigme Namgyal became Trongsa Penlop, the post was one of the most coveted posts in Bhutan.
Jigme Namgyal fought various wars, treacheries and even mighty British to keep country independent and united. As Trongsa Penlop, he designed future destiny for the country. In 1882, Ugyen Wangchuk became Trongsa penlop from where he fought last civil war and from where he became first king of Bhutan in 1907, from where he accompanied Younghusband to Tibet to negotiate Indo-Tibetan treaty in 1904.
After that almost every king assumed post of Trongsa Penlop except for Third Druk Gyalpo making it one of the true heritages of Bhutanese Throne. The investiture as Trongsa Penlop became the formal status of Crown Prince as future king of Bhutan. The appointment of Crown Prince of Bhutan to Choetse penlop represents the crown prince as leader of whole dzongkhag.
In 2004, with the formal awarding of the Gyalse Ngadun, His Majesty the 5th King became 16th Choetse Penlop, a step before he assumed the Throne of Druk Gyalpo in 2006.
For My Own Reference