The Dalai Lama, who turns 80 tomorrow, was guest of honour at the Global Compassion Summit at the Honda Center in Anaheim, south of Los Angeles, speaking on "awakening compassion" and the "transformative power of creativity and art."
His fans said they were delighted to mark the occasion with the Tibetan spiritual leader.
"This milestone occasion is a joyous opportunity for people to come together in celebration of His Holiness' life and achievements," said Venerable Lama Tenzin Dhonden, founder of the non-profit Friends of the Dalai Lama.
But not everyone is celebrating his birthday in California: protests were staged outside the conference center by Shugden Buddhists, who revere a deity denounced since 1996 by the Dalai Lama -- whom they accuse of religious persecution.