Khedrubje Gelek Pelzang (mkhas grub rje dge legs dpal bzang) was born in Tsang in 1385. His father, Gunga Tashi Pelzang (kun dga' bkra shis dpal bzang, d.u.), was a member of the Se clan, said to have originated in Khotan, and his mother was Budren Gyelmo (bu 'dren rgyal mo, d.u.).
His name Gelek Pelzang was given to him as a child when he took novice ordination at the age of seven from Khenchen Sengge Gyeltsen (mkhen chen seng ge rgyal mtshan, d.u.). From the age of sixteen he studied at the Sakya monastery of Ngamring Chode (ngam ring chos sde), training with Bodong Paṇchen Jikdrel Chokle Namgyel (bo dong paN chen 'jigs bral phyogs las rnam rgyal, 1376-1451), the founder of the Bodong tradition, who taught him logic and philosophy.
When Gelek Pelzang was twenty-one he studied with Rendawa Zhonnu Lodro (red mda' ba gzhon nu blo gros, 1349-1412), with whom he took full ordination. He studied Darmakīrt's Pramāṇavārttika, Abhidharma, and the Five Books of Maitreya, Nāgārjuna's works on Madhyamaka, and the Vinaya.
At the age of twenty-three, in 1407, he went to U to meet with Tsongkhapa Lobzang Drakpa (tsong kha pa blo bzang grags pa, 1357-1419) at Sera Choding (se ra chos sdings) a hermitage above the site where Sera Monastery (se ra dgon) would soon be established. Gelek Pelzang received instructions on both sutra and tantra from Tsongkhapa, and soon became one of his most devoted disciples, receiving teachings alongside Tsongkhapa's other disciples such as Gyeltsabje Darma Rinchen (rgyal tshab rje dar ma rin chen, 1364-1432) and Duldzin Drakpa Gyeltsen ('dul 'dzin grags pa rgyal mtshan, 1374-1434).
Gelek Pelzang returned to Tsang and assumed the abbacy of Changra Monastery (lcang ra). He also founded the monasteries of Riwo Dangchen (ri bo 'dangs chen) and, at age thirty-four, was involved in the establishment of Pelkhor Chode (dpal 'khor chos sde) in Gyantse (rgyal rtse), under the patronage of the Gyantse king, Rabten Kunzang Pak (rab brtan kun bzang 'phags, 1389-1442).
At the age of forty-seven, in 1431, Gelek Pelzang was asked by Gyeltsab to take the golden throne of Ganden (dga' ldan gser khri), becoming the third man to occupy the seat after Tsongkhapa and Gyeltsab Darma Rinchen (rgyal tshab dar ma rin chen, c.1364-1432).
At Ganden Khedru taught extensively, gave many initiations, and personally guided some of the most renowned scholars of the era to mastery of the tradition. He passed away there in 1438, at the age of fifty-three.
He was posthumously given the title of First Paṇchen Lama by virtue of being considered a pre-incarnation of the Fourth Paṇchen, Lobzang Chokyi Gyeltsen (blo bzang chos kyi rgyal mtshan, 1570-1662).
Images

Khedrubje Gelek Pelzang
To the left, Khedrupje is depicted while thinking of his great teacher, Tsongkhapa, who appears above him on a cloud. On the middle right, Khedrubje is making an offering to Tsongkhapa. On the lower right, Khedrubje is seated while editing a manuscript.

Khedrubje Gelek Pelzang
To the left, Khedrupje is depicted while thinking of his great teacher, Tsongkhapa, who appears above him on a cloud. On the middle right, Khedrubje is making an offering to Tsongkhapa. On the lower right, Khedrubje is seated while editing a manuscript.

Khedrubje Gelek Pelzang
To the left, Khedrupje is depicted while thinking of his great teacher, Tsongkhapa, who appears above him on a cloud. On the middle right, Khedrubje is making an offering to Tsongkhapa. On the lower right, Khedrubje is seated while editing a manuscript.

Shakyamuni Buddha
The central figure of Shakyamuni Buddha is shown with Tsongkhapa and primary disciples in the upper left corner. Below are protector deities.
Bibliography
Cabezon, Jose Ignacio. 1992.A Dose of Emptiness: An Annotated Translation of the sTong thun chen mo of mKhas grub dge legs dpal bzang. Albany: State University of New York Press.
Grags pa 'byung gnas. 1992.Gangs can mkhas grub rim byon ming mdzod. Lanzhou: Kan su'u mi rigs dpe skrun khang, pp. 219-221.
Sde srid sangs rgyas rgya mtsho. 1989 (1698).Dga' ldan chos 'byung baiDU r+ya ser po. Beijing: Krung go bod kyi shes rig dpe skrun khang, p. 75-76
Tshe mchog gling yongs 'dzin ye shes rgyal mtshan. 1970 (1787).Byang chub Lam gyi Rim pa'i Bla ma Brgyud pa'i Rnam par Thar pa Rgyal mtshan Mdzes pa'i Rgyan Mchog Phul byung Nor bu'i Phreng ba. New Delhi: Ngawang Gelek Demo, vol 1, pp. 877 ff.