Koh-i-Noor leaves India for Persia, for the first time (1540-1547)

The Shah of Iran Thamsap I, received him cordially and granted him exile. Eventually he promised him military aid to regain his kingdom, provided he became a Shiite Muslim, and returned Qandahar to Iran, in the event of it's successful capture from the Afghan rulers.

Humayun waited until the death of Sher Shah (May 1545), and during the period of his successor Islam Shah (1553), he began his military campaign to regain his lost Kingdom. At first he captured Qandahar and Kabul, and in Dec 1554 crossed the Indus and marched to Lahore, which he captured without opposition. In Feb. 1555, he occupied Sirhind and in July 1555, captured Delhi and Agra. He thus regained the throne of Delhi, and was re-united with his family after an interval of 15 years. But, Humayun did not live long to recover the whole of the lost Empire. He died six months later, as a result of an accident, in Jan. 1556. The news of his death was kept a secret for about two weeks, until the peaceful accession of his son Akbar, who was 13 years old and was at the time away in Punjab as it's Governor.

It is said that Humayun carried the large diamond which his father gave him, when he went into exile in Iran. While in Iran, he was so kindly treated by the Shah, that as an expression of gratitude he presented the Babur Diamond and other jewels to Shah Thamsap. This is mentioned in the Akbarnama-Memoirs of Akbar- written by the historian Abdul Fazal, who was later appointed as secretary to the Emperor Akbar. The presentation of the diamond to the Shah was also confirmed by Khur Shah, the Ambassador of Ibrahim Qutb, King of Golconda, at the Persian Court. He said that a diamond of six mishquals, was presented to the Shah, that was worth the expenditure of the whole world for 2½ days, a familiar way of appraising the Babur Diamond. However, he also said that Shah thamsap was not so impressed and later sent it as a gift to Burhan Nizam (1509-1553), the Shah of Ahmednagar. These events took place in 1547.