Founder of Sikhism, spiritual leader and teacher Guru Nanak was born April 15, 1469.
(This date is generally quoted as his birth date)

Let mercy be the cotton, contentment the thread,
Continence the knot and truth the twist.
Oh priest! if you have such a thread,
Do give it to me.
It will not wear out, nor get soiled, nor be burnt, nor lost.
Says Nanak, blessed are those who go about wearing such a thread.
(Rag Asa)
Guru Nanak – SikhiWiki, free Sikh encyclopedia.

550th Anniversary of Birth of Guru Nanak  
Issued 2019 by India Post
Designer: Kamleshwar Singh

Bābā Nānak “was an Indian spiritual teacher who is revered as the founder and the first Guru of Sikhism, a monotheistic religion that combines Hindu and Muslim influences.”
https://www.britannica.com/biography/Guru-Nanak