Sikhs across the world are celebrating the 550th anniversary of the birth of their first Guru - Guru Nanak Dev Ji. It's commonly called Gurpurab.
Gurdwaras (Sikh temple) and community centres across our region have been singing hymns, serving food and holding firework displays.
The date of the celebrations changes each year, but this year it falls on Tuesday 12th November. It occurs on the day there is a full moon.
During Gurpurab, Gurdwaras are decorated with flags, lights and flowers.
On the morning of the anniversary, celebrations begin early in the morning and people sing hymns, read poems and have lectures on Sikhism.
Just like this Gurdwara in Southsea.
Raiminder Singh, Gurdwara spokesman:
The biggest celebrations happen in at the Sikh's most holiest place on earth, Harmandir Sahib or The Golden Temple, in Amritsar, North India.
Words of celebration and thanks were tweeted from all walks of life, including Prime Minister Boris Johnson and the Prime Minister of India.
Who was Guru Nanak Dev Ji?
Guru Nanak Dev Ji was born into a Hindu family in 1469 in North Punjab (now in Pakistan since 1947).
When he was 30 years old he mysteriously disappeared for three days.
He then reappeared and began to build the foundations of Sikhism.
Guru Nanak Dev Ji spent the rest of his life teaching, writing and travelling around the world to discuss religion with people from all faiths.