In 1689 the Emperor in person led an army against him, crossing the deadly desert of Gobi for this purpose.
Finally, after a further expedition and a decisive defeat in 1693, Galdan became a fugitive, and died three years afterwards.

He was succeeded as khan by his nephew, Arabtan, who soon took up the offensive against China.

He invaded Tibet, and pillaged the monasteries as far as Lhasa; but was ultimately driven back by a Manchu army to Sungaria, where he was murdered in 1727.
The question of the calendar early attracted attention under the reign of K`ang Hsi.

After the capture of Peking in 1644, the Manchus had employed the Jesuit Father, Schaal, upon the Astronomical Board, an appointment which, owing to the jealousies aroused, very nearly cost him his life.

What he taught was hardly superior to the astronomy then in vogue, which had been inherited from the Mongols, being nothing more than the old Ptolemaic system, already discarded in Europe.