Only just pre-1950s, the current Dalai Lama was born in 1935.
Starting half-way through this page, At Home With the Dalai Lama, is an account of his learning to meditate (and probably of being forced to learn to meditate), at age 8.
I also know that he wasn't a particularly good student when he was
young. He had a mercurial temper and was impulsive. Monastic
disciplines like meditation and scriptural study did not come
naturally to him.
"Around seven or eight," the Dalai Lama told me in an earlier meeting,
a mischievous gleam in his eyes, "I had no interest in study. Only
play. But one thing: my mind since young, quite sharp, can learn
easily. This brings laziness. So my tutor always keep one whip, a
yellow whip, by his side. When I saw the yellow whip, the holy whip
for holy student the Dalai Lama, I studied. Out of fear. Even at that
age I know, if I study, no holy pain."
Despite his reluctance to study when he was a child, the Dalai Lama
applied himself every morning. With perseverance and self-control, he
learned to sit still for long periods. Gradually he was better able to
control his errant impulses. Meditation and study came before play;
delayed gratification became a matter of course.
Reading this gives me the impression that the curriculum which the Dalai Lama learned was passed down through successive generations/incarnations.
The Speech Delivered by His Holiness 14th Dalai Lama to the
Second Gelug Conference
(Dharamsala, June 12th 2000) says,
Now it is about six hundred years since Lama Tsong Khapa lived in Tibet. About three hundred years
earlier, Dipamkara Atisha founded the great Kadam tradition. It was this school that Lama Tsong Khapa
used as his foundation. He started a tradition that emphasised tantric study that concentrated on practices
of the three deities, Guhyasamaja, Heruka Chakrasamvara and Yamantaka.
“May this tradition of the Conqueror, Losang Dragpa,
That teaches the outward, calm and controlled demeanour of the hearer,
And the internal poise associated with the two stages of the yogic practitioner,
And adopts both Sutra and Tantra as mutually complementary paths flourish.”
And as to what is achieved through the adoption of such a practice, we have the words:
“May this tradition of the Conqueror, Losang Dragpa
That takes the emptiness explained in the Causal Vehicle (sutra),
And the great bliss that is achieved through the Resultant Means (tantra),
Conjoined with the essence of the collection of eighty-four thousand teachings flourish.”4
Having all of these features then, this doctrine is a consummate one. It incorporates study, contemplation
and meditation in balanced, equal measure and this is what makes it so remarkable. When it comes to
detailed study of the great texts, it is the Sakya and Gelug systems which are the most developed.