Short answers, pulled from the story.
Qachuli was the progenitor of the Barlas clan and the twin brother of Qabul Khan, the founder of the Khamag Mongol Confederation. Historical records from the Secret History of the Mongols and the chronicles of Rashid al-Din Hamadani confirm this direct bloodline relationship. This connection wove the Barlas into the fabric of Mongol imperial destiny from the early twelfth century.
The Barlas clan transitioned to a settled aristocratic power during the reign of Genghis Khan when Qarachar Barlas was appointed as a Darughachi of Transoxiana. This strategic migration occurred in the thirteenth century and established new settlements in the region that became modern-day Shahrisabz in Uzbekistan. The tribe adopted a sedentary existence and intermingled with the native Turkish population of the valley of Kashka Darya during this period.
Timur established the Timurid Empire in the fourteenth century with rule extending over modern-day Iran, Armenia, Azerbaijan, Georgia, and almost the entire rest of the Caucasus. The empire also covered Afghanistan, much of Central Asia, parts of contemporary Pakistan, Mesopotamia, and Anatolia. This vast domain rivaled the Mongol Empire in scale and ferocity while blending Mongol traditions with Persian and Islamic arts.
Babur, a direct descendant of Timur and a member of the Barlas tribe, founded the Mughal Empire in the Indian subcontinent. The Mughal Empire extended Barlas influence from Central Asia to the fertile plains of India and became one of the most powerful empires in history. Babur's descendants, including Akbar, Jahangir, and Shah Jahan, continued to rule India for centuries and built iconic structures like the Taj Mahal.
The Barlas tribe gradually gave up their native Mongol language in favor of Chagatai, a Turkic language of the Qarluq branch. This cultural assimilation was a calculated adaptation that allowed the Barlas to integrate into the complex political landscape of Transoxania while retaining their military prowess. The Chagatai language was heavily influenced by Arabic and Persian and facilitated their role as a bridge between Mongol military tradition and settled Islamic civilization.