Guru Har Gobind ji (Gurmukhi: ਗ੝ਰੂ ਹਰਿ ਗੋਬਿੰਦ) (Saturday, 5 July 1595 - Tuesday, 19 March 1644) was the sixth of the Ten Gurus of Sikhism. He became Guru on 11 June 1606 following in the footsteps of his father Guru Arjan Dev ji. While the ceremonial rites were being performed by Baba Buddha ji, Guru Hargobind ji asked Baba Buddha to adorn him with a sword rather than the Seli of Nanak which had been used previously by the earlier Gurus.
Guru Hargobind then put on not one but two swords; one on his left side and the other on his right. He declared that the two swords signified "Miri" and "Piri", "Temporal Power" and "Spiritual Power", one which would smite the oppressor and the other which would protect the innocent. He told his followers: "In the guru's house spiritual and mundane powers shall be combined". "My rosary shall be the sword-belt and on my turban I shall wear a Kalgi" (an ornament for the turban, which was then worn by Mughal and Hindu rulers).
Guru Hargobind carried the same light of Guru Nanak; but he added to it the lustre of the sword. Guru Hargobind sahib ji was also the inventor of the Taus. Guru ji watched a peacock singing one day, and wished to make a instrument to mimic the same sound as the peacock, thus came the Taus.

Arming and martial training

During his captivity, when the Saintly and peaceful Guru Arjan was under the severest torture, he concentrated and relied on God for guidance to save the nascent Sikh Sangat from annihilation. The only solution revealed to him was to guard it through the use of arms. He pondered over the problem again and again and finally concluded that the militarisation of Sikhism had become a necessity. Hence he sent a Sikh disciple to his young son, the eleven year old Har Gobind, nominating him as the Guru of the Sikhs (his devotees), giving him Guru Arjan's last injunction; "Let him sit fully armed on his throne and maintain an army to the best of his capacity".
Guru Hargobind ji excelled in matters of state and his Darbar (Court) was noted for its splendour. The arming and training of some of his devoted followers began, the Guru came to possess seven hundred horses and his Risaldari (Army) grew to three hundred horsemen and sixty gunners in the due course of time. Additionaly five hundred men from the 'Majha area of Punjab' were recruited as infantry. Guru Har Gobind built a fortess at Amritsar called 'Lohgarh' (Fortess of steel). He had his own flag and war-drum which was beaten twice a day. Those who had worked to have Guru Arjan destroyed now turned their attention and efforts to convincing Jahangir that the fort, the Akal Takhat and the growing Risaldari were all intended to allow Guru Hargobind ji to one day take revenge for his father's unjust death.

Akal Takht

Guru Hargobind constructed the Akal Takht (God's throne) in front of Harmandir in 1606. There he sat on a raised platform of twelve feet, attired in princely clothes. The Harmandir Sahib was the seat of his spiritual authority and the Akal Takht was the seat of his temporal (worldly) authority. This marked the beginning of Sikh militarisation. To the symbols of sainthood were added marks of sovereignty, including the umbrella and the Kalgi. Guru Har Gobind administered justice like a King and awarded honours and meted punishment, as well. The Akal Takht was the first Takht in the history of the Sikhs. According to Cunningham: "The genial disposition of the martial apostle led him to rejoice in the companionship of a camp, in the dangers of war, and in the excitements of the chase".

State within a state

The Sikhs had formed a separate and independent identity that had nothing to do with the government agencies of the day. Thus the Sikh entity came to occupy a sort of separate state within the Mughal Empire.

Congregational prayers

Guru Har Gobind ji established Congregational prayers adding to religious fervour among his Sikhs, but also strengthened their unity and brotherhood. Mohsin Fani, author of 'Dabistan', states that when a Sikh wished for a favour or gift from God, he would come to assembly of Sikhs and request them to pray for him; even the Guru asked the Sikh congregation to pray for him.