Henry seems to have been the Old Pretender's favorite son, though he maintained a good relationship with his older brother while they were growing up. Â In 1745, Charles Edward praised Henry to his Scottish followers, assuring them that he was very high-spirited and intelligent.
Henry was left behind in France when Charles Edward made his attempt in Scotland. Â Henry kept the French court informed of Charles Edward's successes, and was eventually given permission to bring some troops and munitions to his brother. Â Due to communication problems, Henry's troops and supplies never left France, since he didn't know whether he should take them to Scotland or England, which ports were safe, etc. Â On his return, Charles Edward fought with Henry over his failure to bring over the troops and supplies; he seems to have held a grudge against him for the rest of his life.
Henry took religious vows soon after his brother's return, to the dismay of Charles Edward, who saw Henry's decision as yet another betrayal. Â
According to John MacLeod's "Dynasty: The Stuarts", Henry chose a religious life because he was gay and had no wish to marry.