Ralong ‘Karma Rabtenling’ Monastery is the first monastery of Kagyupa lineage built by Sikkim’s fourth Ruler Chhogyal Gyurmed Namgyal in Iron-Dog year of 12th Rabjung cycle year, which corresponds to 1730. A.D.
History:
The fourth Ruler of Sikkim, Chhogyal Gyurmed Namgyal (1707-1734), out of distress caused by internal strife, disguised himself as a religious mendicant and went on a pilgrimage to Tibet.

No one in that country suspected his royal origin, until he came before H.H. Changchhub Dorje, the 12th Karmapa (1703-1732),who recognized and gave him a warm welcome. The King was indeed surprised and felt himself embarrassed, as he was totally unprepared and had nothing to offer to such a dignified Lama. Therefore, he offered a promise to Karmapa Lama that he would build a monastery of his Sect in Sikkim and would provide befitting patronage to the monastery.
In the Gazetteers of Sikkim, as mentioned “9th Karmapa ‘Wangchuk Dorje”, is totally a confusion with ‘Changchhub Dorje’ the 12th Karmapa. As per Karmapa Lineage record, the 9th Karmapa Wangchuk Dorje was born in 1556 A.D. and passed away in 1603 A.D. whereas 4th Chhogyal Gyurmed Namgyal’s reign commenced from 1717 to 1733. So history itself reveals that the 9th Karmapa WangchukDorje was not in existence at the time of 4th Chhogyal Gyurmed Namgyal. The Chhogyal, after return from Tibet, built a Karmapa monastery at Ralong in the year 1730 A.D. and offered Bhutia and Lepcha villages falling in the regions between River Tista and Rangit namely Barfung, Lingdam, Burmiok, Temi, Sangmoo, Yangang and Lingmoo as Jindag (Patron) for the newly built monastery.     
On its completion, the Rabney (consecration) ceremony was said to have performed by 12th Karmapa himself from Tibet. Amazingly, some Rabney grains fell on the roof of the monastery at Ralang, which was witnessed by all present there. A few of these grains were said to have possessed of by some lamas. The devotion and faith had taken root in people’s mind and soon monasteries of its kind spread to other parts of Sikkim. In the beginning of 19th century, an incarnation of one Omdze Lama of Shamarpa lineage was born to the family of Chhoedten Kalon in the village of Barfung, who was later enthroned as the Head Lama of Ralong Gonpa by 14th Karmapa Thegchog Dorje.
During the tenure of this Lama, the monastery was rebuilt with bigger size as the earlier one became old and comparatively small to accommodate the increasing number of monks. When the monastery was complete, once again the Rabney ceremony was performed from Tshorphu, Tibet, but this time performed by 14th Karmapa Thegchog Dorje (1798-1863). On this occasion, many auspicious signs were observed, such as showering with rainbows and appearance of a Vulture that circumambulated three times to the monastery and thereafter flew towards northeast hill called- ‘Mainam’.