Background: Timur was born in Transoxiana near the city of Kesh (modern Shahrisabz, Uzbekistan) some 80 kilometres (50 mi) south of Samarkand, part of what was then the Chagatai Khanate. His father, Taraqai, was a minor noble of the Barlas, a Mongolian tribe that had been turkified in many aspects. According to Gerard Chaliand, Timur was a Muslim, and he saw himself as Genghis Khan's heir. Though not a Borjigid or a descendent of Genghis Khan, he clearly sought to invoke the legacy of Genghis Khan's conquests during his lifetime.
Context: Timur spent the next 35 years in various wars and expeditions. He not only consolidated his rule at home by the subjugation of his foes, but sought extension of territory by encroachments upon the lands of foreign potentates. His conquests to the west and northwest led him to the lands near the Caspian Sea and to the banks of the Ural and the Volga. Conquests in the south and south-West encompassed almost every province in Persia, including Baghdad, Karbala and Northern Iraq.  One of the most formidable of Timur's opponents was another Mongol ruler, a descendant of Genghis Khan named Tokhtamysh. After having been a refugee in Timur's court, Tokhtamysh became ruler both of the eastern Kipchak and the Golden Horde. After his accession, he quarreled with Timur over the possession of Khwarizm and Azerbaijan. However, Timur still supported him against the Russians and in 1382 Tokhtamysh invaded the Muscovite dominion and burned Moscow.  In 1395 Tamerlane reached the frontier of Principality of Ryazan, took Elets and advancing towards Moscow came near the banks of the Don River. Great Prince Vasily I of Moscow went with an army to Kolomna and halted at the banks of the Oka River. The clergy brought the famed Theotokos of Vladimir icon from Vladimir to Moscow. Along the way people prayed kneeling: "O Mother of God, save the land of Russia!" Suddenly, Tamerlane's armies retreated. In memory of this miraculous deliverance of the Russian Land from Tamerlane on August 26, the all-Russian celebration in honor of the Meeting of the Vladimir Icon of the Most Holy Mother of God was established.
Question: What happened at the beginning of Timur's expansion period?

Answer:
Timur spent the next 35 years in various wars and expeditions. He not only consolidated his rule at home by the subjugation of his foes, but sought extension of territory