Rudi was aware of his spiritual potential as a young boy and spoke of continual inspirational visions and experiences that guided him onto his spiritual path. His earliest teachers were Tibetan Buddhists, and he studied the teachings of Gurdjieff and Pak Subud in his early twenties. The greater portion of Rudi’s studies were spent with Hindu masters: Sri Shankarcharya of Puri, Bhagavan Nityananda, and Swami Muktananda, who, in 1966, recognized Rudi as a swami, and gave him the name Swami Rudrananda.

While Rudi had several teachers, it was his relationship with Bhagavan Nityananda that catapulted his growth into its most profound dimensions. Rudi said, "My first meeting with the renowned Indian guru, Bhagavan Nityananda, was of such a depth that it changed the course of my life.” Although Rudi only met Nityananda a few times, it was the relationship that developed with him after his passing that was the most important part of his connection to Nityananda. Rudi described this relationship as existing on a profound spiritual level that was not limited by the non-presence of the physical form of Nityananda.

Bhagavan Nityananda

Nityananda, whose name means "bliss of the eternal," lived in southwest India from around the turn of the 20th century until 1961. Details of his early life are difficult to verify, but from the 1920s until his passing, he was surrounded by an ever-increasing number of disciples and devotees. By the late 1930s he was established in Ganeshpuri, a small village in the countryside near Mumbai, and an active ashram developed around him.

Nityananda would come into a small room in the ashram that was lit by a few bare electric light bulbs, and sit there quietly with his eyes open. People would come from all distances to see him because, in India, the mere viewing of a spiritual teacher, called darshan, is considered a profound and important blessing. Nityananda would sit in this space with his eyes open, establishing a connection with each visitor according to his or her capacity to experience and sustain that contact.

Nityananda was well known in India, where he is revered to this day as a great saint. In its essence, Nityananda's teaching is profoundly simple. Like the ancient sages of many traditions, he said that anyone who merges the individual into the universal is an enlightened person. To realize the universal nature of one's own individual consciousness is the goal of sadhana (spiritual practice). However, it is hard to describe Nityananda's greatness to most Westerners since his most profound achievements were internal.

In the Nityananda Sutras, he speaks of eight aspects that are the essence of his experience and therefore of his teaching. They are: developing the subtle discrimination of seeing the One in the many, detachment, devotion, inner practice, living in profound simplicity, discovering unconditional joy, living in Grace,  and communion with the divine. Nityananda clearly emphasized the awakening of the kundalini as the path to liberation. The powerful forces of shaktipat were continuously emitted from him and permeated the environment around him.

After the age of 30, he rarely spoke at all. The thousands of people who came to see him did so because in him they experienced the miracle of pure consciousness in human form. Such a holy person is called an avadhut. Timeless and eternal, the avadhut is a direct link to the absolute, encompassing all teachers who precede him and all who follow.
You can learn more at http://www.nityanandatradition.org or  http://www.nityananda.us

Swami Muktananda

After Nityananda took maha-samadhi, Rudi became the student of Swami Muktananda, one of Nityananda’s primary students. Rudi studied with Muktananda for 10 years, until 1971. Rudi had profound respect for Muktananda and spent years working to receive the nourishment and guidance made available to him through Muktananda. He recognized that Muktananda was an integral part of his own attempt to deeply open to and receive the grace of Nityananda that was pouring into him. Rudi and Muktananda were like two major branches emerging from the trunk of a giant oak tree that was Nityananda. There are Muktananda and Rudi disciples who have acknowledged that they are in the same tradition, maintain friendly relationships and do work together.

Swami Muktananda, widely known as Baba, was born in 1908. Beginning his spiritual search at 15, he walked across India, studied Sanskrit, read the scriptures, became an adept hatha yogi and took the vows of sannyas. His sadhana culminated under his Guru, Bhagavan Nityananda of Ganeshpuri. Muktananda is recognized as one of the key people who propagated the lineage that emerged from Nityananda. Muktananda left quite a number of disciples to carry on his teaching.

Muktananda made a powerful impact on the West during many world tours in the 1970s, (the first sponsored by Rudi) when he awakened thousands of seekers through shaktipat. He founded a worldwide organization of ashrams and centers, published many books and offered numerous retreats and intensives. He also was instrumental in bringing the powerful teachings of Kashmir Shaivism to the West. He died in 1982.
You can learn more at http://www.siddhayoga.org/guru/muktananda.aspx