For students of the 〈 菩提道次第廣論 〉(Lamrim), 宗喀巴大師 will be known to you as the author of the treatise.
We can easily get information from Wiki about 宗喀巴大師 (Je Tsongkhapa).
However, to get a more in-depth awareness of this great Teacher of Buddhism, we can turn to 如得法師 and his video series.
Check it out here, Episode 1:
In our Lamrim classes, we also recite the 密集玛 (or Migtsema: A Prayer to Jé Tsongkhapa).
Understanding the meaning behind the mantra helped me to better visualise this great guru during my recitation.
Sharing some resource here for our reference:
Migtsema: A Prayer to Jé Tsongkhapa
http://www.rigpawiki.org/index.php?title=Migtsema:_A_Prayer_to_Jé_Tsongkhapa
mikmé tsewé terchen chenrézik
drimé khyenpé wangpo jampal yang
düpung malü jomdzé sangwé dak
khangchen khépé tsukgyen tsongkhapa
lobzang drakpé shyapla solwa dep
Great treasury of non-referential compassion, Avalokiteshvara,
Powerful lord of flawless wisdom, Manjushri,
And destroyer of all the hosts of mara, Vajrapani, Lord of Secrets—
Crowning glory amongst all the learned masters of the Land of Snows,
Tsongkhapa Lobzang Drakpa, at your feet I pray!
Lama Tsongkhapa’s Migtsema
http://www.lama-tsongkhapa.com/migtsema/
MIG MEY TZE WAY TER CHEN CHENREZIG
DRI MEY KHYEN PI WANG PO JAMPAL YANG
DU PUNG MA LU JOM DZEY SANG WEY DAG
GANG CHENG KE PEY TSUG GYEN TSONGKHAPA
LO SANG TRAG PEY SHAB LA SOL WA DEB
Objectless compassion, Chenrezig,
Lord of stainless wisdom, Manjushri,
Conquering mara’s horders, Vajrapani,
Crown jewel of the Sages of the Land of Snows, Tsongkhapa,
Losang Drakpa, at your feet, I pray.
密集嘛 - the Chinese Version (used in BW Monastery)
Venerable Ru Jun talks about how hard it is to encounter Je Tsongkhapa’s teaching -
宗大师教法难可值遇
I learn today that I should supplicate that I can receive Je Tsongkhapa’s teachings in every lifetime:
无垢净愿者,生生世世学弘宗大师显密清净圆满教法
And to do this, we should supplicate that we can meet our Teachers and Gurus that have the lineage to Je Tsongkhapa’s teachings.
一定要遇到这个圆满教法的传承师长
Venerable Ru Jun mentions in his discourse (from 9:11 min mark) that:
宗大师是众生未曾认识的大亲友
My translation: Master Tsongkhapa is the great relative that sentient beings have not become familiar with
也可以说所有的佛菩萨，祖师，我们说依止的师长都是众生未曾认识的大亲友
My translation: we can also say that all the Buddha and Bodhisattva, Masters and the Teachers we rely on are the great relatives that sentient beings have not recognised
I find this line of thinking apt.
Hoping that more of us can get closer to these Great Relatives!
My class shared some videos on Master Tsongkhapa.