This is taken from http://www.sikhiwiki.com/
As the year approaches the end, on December 28 every year, the global world Sikh community commemorate the martyrdom of three of their most loved figures of the Guru household. On this darkest of days, their youngest hero and bravest comrade of Sikhism, Sahibzada Fateh Singh (1699-1705) who was the youngest of Guru Gobind Singh's four sons, Sahibzada Zorawar Singh (1696-1705), his elder brother and Mata Gujar Kaur ji, his grandmother sacrificed their lives for their faith and the right to remain Sikhs.
Gurdwara Fatehgarh Sahib which is situated 5 km north of Sirhind marks the sad site of the execution of the two younger sons of Guru Gobind Singh at the behest of Wazir Khan of Kunjpura, the faujdar of Sirhind. The three shrines exist within this Gurdwara complex to mark the exact spot where these tragic events were witnessed in 1705.
Baba Fateh Singh with his elder brother, set a precedence in Sikh history (and perhaps also in world history) by becoming the youngest known martyrs to sacrifice their lives for their principles and the right to practice their religion and their faith without coercion or the threat of terror. Even at such a tender age of 6 years, Baba Fateh Singh showed courage, determination and free-will not to be intimidated by the cruel, barbaric and unjust authorities of the time. He showed composure, fearlessness and the renowned trait of unparalleled heroism becoming of the Sikh leadership and was prepared to sacrifice his life but not his faith.
The mind boggles to understand how children of such young age had the guts, courage, bravery and focus to refuse the promise of many lavish gifts and a future of cosy comforts of royalty that were being offered by the Mughals if they abandoned their faith against the other stark option of a brutal, painful and tragic death entombed within a wall of bricks and mortar. The world salutes the supreme sacrifice of these kids of steel who never once - even of a moment considered the easy option and always remained focused on their mission to uphold the principles of God's kingdom and allowed their bodies to be tortured and violated and endured the intense pain of a slow, pain-ridden and certain death.
On the one hand the world witnessed, the supreme sacrifice of the youngest members of the Guru household for the highest ideals of humanity and on the other hand you have the lowly, cruel, cold-blooded and barbaric acts of the mighty, heartless and immoral rulers of a huge nation. May the world reflect on this grim and gutless episode in the history of humanity and learn from it the values of life and the way to uphold these values and the dangers posed by an uncontrolled and immoral mind.
On 26 December 1705, Baba Fateh Singh ji was cruelly and mercilessly martyred at Sirhind along with his elder brother, Zorawar Singh. He is probably the youngest recorded martyr in history who knowingly and consciously laid down his life at the very tender age of 6 years. Sahibzada Fateh Singh and his older brother, Sahibzada Zorawar Singh are among the most hallowed martyrs in Sikhism.
As soon as the two Sahibzadas attained martyrdom, Mata Gujri ji, who was sitting in meditation in the tower, breathed her last. The messenger who came with the news of the martyrdom of the Sahibzade found that Mata-Ji had already attained salvation. There was great commotion in the town of Sirhind. Everyone was furious at the atrocious crime. They were unanimous in their view that this heinous act would herald the doomsday of the Mughal Empire. They admired the courage and steadfastness of the brave sons of Sri Guru Gobind Singh Ji and remarked, "What determination at such a young age! They did not budge an inch from their position in spite of several allurements by the Nawab and Qazi."
The same evening Dewan Todar Mal, a jeweller reached Nawab Wazir Khan's court for permission to cremate the dead bodies of the two Sahibzadas and Mata Gurji. So as to highlight the extreme cruelty of the administration, the Nawab agreed on condition that the dewan paid for the required piece of land by spreading as many Gold coins as would cover the entire spot. The dewan accepted the terms and brought bagfuls of gold coins to satisfy the condition set by the Mughal administration. He marked the site and spread coins on entire piece of land he selected for cremation. The two martyred young sons of Sri Guru Gobind Singh Ji were cremated with full honours along with their grand mother.
There is no parallel to the martyrdom of such young boys in the annals of human history. Sahibzada Fateh Singh was less than six years old (born 1699) and Sahibzada Zorawar Singh was just over eight (born in 1696). They laid down their lives in December 1705. At such a tender age, they were bricked alive but did not bow before the tyranny and cruelty of the Mughal government. Sri Guru Gobind Singh Ji was at the time in the forests of Machhiwara when the news of the martyrdom of his younger sons reached him. On hearing this he pulled out a plant with the tip of his arrow and prophesized that this tragedy will herald the uprooting of Mughal Empire in India. And to the Emperor he wrote in the Zafarnama: "…Even though my four sons were killed, I remain like a coiled snake. What bravery is it to quench a few sparks of life?..... When God is a friend, what can an enemy do, even though he multiplies hundred times? If an enemy practices enmity and hatred a thousand times, he cannot, as long as God is a friend, injure even a hair on one’s head."
Sri Guru Gobind Singh Ji addressed his followers and reassured them thus: "Although, four of my sons have joined Waheguru, many thousands of my sons are still alive", meaning that the Guru accepted all Sikhs as his sons and daughters. A wave of anguish gripped the country as the news of the martyrdom of the Sahibzadas spread. After some time the recluse Banda Bairagi came under the influence of Sri Guru Gobind Singh Ji, and was made a Khalsa as was Banda Singh Bahadar. He undertook the task of dealing with these cruel oppressors and shook the very heart of the Mughal empire. The town of Sirhind was reduced to utter ruins as a consequence of the cruel, uncaring and heartless treatment of the Sahibzade.
The renowned Hindi poet, Maithli Saran Gupta in his well known book Bharat Bharati said: "Whatever their present position, the future of the community whose sons can thus lay down their lives for their faith, is bound to be glorious."