Relations between China and the Tibet

The Tibet, since the 7th century, has rather relationships with China for goods and
with India for culture and religion; therefore felt closer to India than to China.
The Emperors of China "Sky's Sons" always considered themself as masters of the people with
whom they traded even when their territories were under the control of foreign leaders.
In effect, the people on the West of the 100th degree East : Tibetan, Kashgarians, Ouïgours, etc..
are not "Hans" and speak rather syllabic languages using an alphabet.
The Tibet protected by hostile living conditions has natural borders but on border with China,
one will find blended populations which have never merged. After the 7th / 9th century
where the kings of the Tibet were as powerful as the Emperor of China, the 2 countries
respected mutually and lived in good understanding.
But in 1578, the Mongolians recognized the Superior de Drepung, head of the Gelugpa school, as Dalai-lama or
the "highest authority" of the buddhist doctrine, and so place a foot in the domestic policy of Tibet.
Numerous monasteries passed Gelugpa. The tensions which followed leads the King du Tibet
and the supporters of the ancient Schools to rebel and to harsch Gelugpas.
The Mongolians are going to intervene and set up the 5th Dalai-lama which
established in Potala and takes the temporal power of the country.
Reports China - Tibet were: laic Protector (China) - religious Master (Tibet).
The emperors Chineses, Mongolians and Manchus recognized the authority
of the Dalai-lamas of Tibet. Unfortunately, in Tibet, quarrels with the Chinese party
or between the different Churches required the return of the Chinese army to restore order.
The Chineses are going to install several garrisons and an Amban (ambassador for Tibetan,
prefect for the Chineses) in Lhasa. The sovereignty of Tibet is complete and during English
expedition in 1904, the Chinese troops were only presenting arms to the British troops passage.
The Tibet which would have been able to have diplomatic exchanges with the exterior
preferred remaining dumb behind its natural borders and ignore the statements made here and
there on the suzerainty of China on Tibet. Mao in the people liberation's name destroys this balance.
Today we can see two peoples who live nearby and are ignoring each other.