Sri Aurobindo traveled from the then British India (Kolkata port) to the then French India, Pondicherry, under the name of Jyotindranath. Whether it can be called a pseudonym or not is debatable. Names represent quality and that is how Sri Krishna, Arjuna, Lord Vishnu have so many names. Jyotindranath literally means the Lord of the highest Light. It goes perfectly with Sri Aurobindo, though it was not his legal name ever. It also means Lord of Life, a phrase actually used in Savitri.
Affectionately,
Alok Da


