The only credible and authoritative source about Sankaranatha Jyotsar, I could find from sources outside Kerala, was from the link http://www.esikhs.com/articles/a_retrospect.htm under the chapter “The Sikhs - Images of a Heritage” written by T.S.Randhawa.
“The other dramatis personae in the court of Maharaja Ranjit Singh were the Fakir Aziz-ud-din, his Foreign Affairs Minister---- Shankar Nath Joshi, the chief astrologer to Maharaja Ranjit Singh, who was from Travancore and returned there when the bloodbaths started at Lahore”
There is a chapter on Sankaranatha Jyotsar in the Malayalam book by name “Vadakkan Eithihyamala” by Vanidas, Elayavoor, a fine scholar and teacher of Malabar. Much of the information here apparently is from legends sourced from family members. I have relied much on him for the information contained in this post.
Ranjit Singh built a great Sikh empire during the early years of the nineteenth century when the British expanded its territories by conquest or annexation reaching the borders of Punjab.The British could not claim full control over the Indian subcontinent till the fall of Punjab which happened only after the death of Ranjit Singh in 1839. The Second Anglo-Sikh War (1848-49), between the Sikh Empire and the British Empire resulted in the annexation of Punjab which became the North West Frontier Province under the East India Company.
The last decade of the 18th century was one full of fear and insecurity for the people of Malabar. Tippu Sultan was holding his military campaigns for expanding his empire. Many families from Malabar fled to the safer shores of Travancore. Parvathi Amma belonging to the Vengatt Unithiri family of Karivellur and her husband Agni Sharman Nampoothiri of Perinchelloor pattodam Illam were a couple who too were part of this exodus. Parvathi Amma was into last stages of pregnancy and the tedious journey took its toll and she gave birth to a son while resting in a temple for the night.
Sankaranatha was thus born on the 16th of July 1790. His mother was very intelligent and was a scholar in Sanskrit. She wanted her only son to grow up as a learned person. However, the little Sankaranatha was more inclined to playing various games than to attend to his studies. Desperate over this, one day she admonished the son wondering as to how an ass was born in the womb of a horse. Hurt by the remarks, the boy turned a new leaf in his life. He began to show exemplary inquisitiveness in his studies and thus began a life full of learning and wisdom.
He was put under a guru Paliyeri Ezhuthassan, a renowned scholar of the times. He had different teachers for varied subjects like Grammar, Kavya, Alankara, Ayurveda and Jyothisha. He showed great skills beyond his age in learning the subjects and the teachers were often found wanting to answer his doubts.
After his early studies, with the blessings of his teachers, Sankaranatha wanted to pursue higher studies and to travel all over India in pursuit of knowledge by meeting different people. It was difficult for him to get the permission from his mother but his persuasions yielded result as he convinced her of the blessings that would come to the family if he visited Benares and bathed in the Ganges.
Proceeding to Kanchipuram, a city which was the confluence of many scholars, he stayed at the Kamakshi temple. Legend has it that he got an idol of goddess Kamakshi while bathing in the Palar River as per a dream he had the previous night. He knew that the daily worship of the idol would bring all happiness and prosperity.
His journey to Benares was interspersed with visits to many temples and meeting many scholars. Eventually he reached Benares and paid obeisance to Lord Viswanatha and conducted all rituals for the family and the forefathers.
It was at Benares that Sankaranatha started to learn the Vedas in an organized manner. He became a disciple of Varahacharya, a great Vedic scholar of the times. After the studies of the Vedas, he took up his Jyothisha-astrological- lessons in full earnest. His forecasts on the horoscopes were amazingly accurate and these made his fame reach far and wide. Rajahs, local rulers and chieftains sent palanquins to receive him at their residences. Sankaranatha amassed much wealth and used much of the money on philanthropic activities .He constructed an inn by the side of Manikarnika ghat known as Joshi ghat.
Raja Sansar Chand of Kangra
Raja Sansar Chand Katoch of Kangra (1775/1823)–near Dharmasala-by the foot hills of the Himalayas came to Benares and happened to meet Sankaranatha. Greatly impressed by the scholarship and predictive skills of Sankaranatha, the Raja took him to Kangra and appointed him as a scholar in his royal court.
Meeting with Ranjit Singh
On one of his visits to Kangra, Ranjit Singh came in contact with Sankaranatha Jyotsar and was impressed about his wisdom and astrological skills. He invited Jyotsar to Lahore and appointed him in his court as the Chief Astrologer. He was also honored by appointing as the head of the scholars of the royal court and as the spiritual advisor to the Maharaja.
At the Lahore court of Ranjit Singh
Sankaranatha used to represent the Maharaja in many of his discussions with the British resident and often won accolades for his diplomatic skills. He was also given some villages as tax free because of the esteem with which he was held by Ranjit Singh. He was living in the palace quarters itself and used to accompany the Maharaja on his tours. In one of the battles of Ranjit Singh with the Afghans, Sankaranatha too accompanied him in military dress. During this outing, he got a wound on his cheek by the enemy’s sword and the scar was to remain on his face till the end. In that battle, the predictions and encouragements of Sankaranatha was of great help to Ranjit Singh and he was showered with many honours and presents on winning the battle.
Arrival at the court of Swati Tirunal
Swathi Tirunal Maharajah of Travancore, having heard about the genius of Sankaranatha Jyotsar wanted him to be brought to his court. Accordingly he requested the British government for the services of Sankaranatha. On receiving the request, Ranjit Singh realized that the honour and recognition that his courtier deserves from his motherland is of utmost importance and hence gave permission for him to leave.
Lord William Bentinck was the Governor General of India (1828 to 1835) at that time and he understood the special qualities of this statesman. Reportedly, he gave a certificate to Sankaranatha for his safe journey from Lahore to Travancore, addressing it as “’Uthama purush, Nirmala budh Joshi Sankaranath, the spiritual advisor of His Highness Ranjit Singh, the Lion of Lahore.”
Swati Tirunal appointed him as the judge of the Sudder court, which was later to become the high court. While serving here, as per wishes of his mother, he married Lakshmi of Cherukara house in Attukal. He served in the position for 8 years with great distinction. The maharajah had once written to Ranjit Singh asserting that it was a great blessing to Travancore to enjoy the services of Sankaranatha.
Return to Lahore
Under continuous persuasion of Ranjit Singh, Sankaranatha returned to his court in 1835 and served him till his death in 1839. Though he continued to serve the disintegrating and tragedy-struck Sikh empire under Kharak Singh and Sher Singh, he was not comfortable and chose to return to the cooler shores of the south in 1844.
Coming back to Travancore
Hearing about his return, Swati Tirunal again sent for him and he took up the post of Fouzdari commissioner. (The East India Company's Courts were called Sudder Adalat and Fouzdari Adalat which exercised appellate jurisdiction, civil and criminal. These were abolished upon the establishment of the High Court after the crown took over.) His booksWhile he was a great diplomat cum statesman, his knowledge of the Vedas, Upanishads and Vedanta was incomparable. He had written commentaries on various holy texts like Njana Vaasishtam and Devi Bhagavatham. Books named Kasee-khandam and Gowree-thantram are also attributed to him. Many of these books are reportedly at the Manuscripts library of the University of Kerala as mentioned by Dr.Achyut Sankar. Maharajah Swati Tirunal died in 1847 but Sankaranatha Jyotsar continued his services under the illustrious Maharajah Uthram Tirunal with great distinction. The great scholar breathed his last on the 28th day of Thulam in the Malayalam year 1034 while preparing to proceed to the Padmanabha Swamy temple to have darshan of the deity. A trust called Sree Kamakshiyamman Trust has been formed by the members of his family at Karivellur in the Kannur district of Kerala. They unveiled a portrait of the great man on his 215th birthday in 2005. Sadly, I am yet to see a portrait of him which I badly wanted to attach with this post.