The way I've heard it:
His father, King of his region, consulted seers and astronomers at Gautama's birth.
Their reading was that the Prince would either be a great holy man, or a great warrior who would expand the Kingdom significantly. The King asked how to ensure the "Great Warrior" outcome, and the reply was: Make sure he sees no suffering, encounters no death, decay, pain or even discomfort for as long as possible. If he doesn't develop compassion for suffering, he'll be the warrior.

This was done. Flowers were changed daily, seasonal moves from palace to palace hid the facts of death and decay. The kingdom's most beautiful women served at Court, and were replaced while still young and beautiful.

The deal went bad when Gautama saw a corpse and began his own seeking. The intensity and dedication of his search is legendary, as is his compassion.

His result: A significant body of enlightened teachers left to continue his work beyond his lifetime and a religion that still has fruitful branches 2500 years on.

No Master is recorded as leaving as many enlightened disciples as Gautama.