The planet Jacowitz is the oldest planet in the universe. It lies within a binary solar system in the Whirlpool galaxy. It orbits around two different suns, and has three moons. Due to the long life of the Nyklus, it's impossible to say the comparison between Jacowitzian and Earth years.
First came Jacowitz, then the universe was born around it. As each new star was formed, a new Nyklus was born. Which influences the other is unknown, but what is known is that the Nyklus, and their star depend on one another.
Due to the long life of the rulers, Jacowitz goes through a series of 'ages' depending on the ruler.
The First Age - King Corconius
Not a lot is known about the First Age. What is known is that the Nyklus first began to work at their technology during this age, rapidly learning how to use the tools at their disposable to their advantage.
The Second Age - King Thaddeus
During the Second Age, the Nyklus began to speak telepathically and use their telekinetic ability in preference to speaking and moving items physically. The economy boomed as they began trading with their surrounding planets.
The Third Age - King Corvax
The Third Age saw the use of speech become almost extinct. The Nyklus began to be seen as the wisest of the surrounding races, often being visted by surrounding planets for advice.
The Fourth Age - King Jannuela
King Jannuela wasn't king for very long in comparison to his ancestors, but the changes he made became obvious. He had an eye for exotic animals and began exporting them from neighbouring planets, breeding them successfully. Jacowitz became home to species which found themselves extinct on other planets.
The Fifth Age - King Salumepe
King Salumepe was seen to be a fairly lazy king. If it weren't for his son, and his advisors, the planet might have slipped back into a dark age. It was during the Fifth Age that the Sontarans first attacked the planet.
The Sixth Age - King Laksmono
The Sixth Age saw Jacowitz join with neighbouring planets in a Treaty of Protection. King Laksmono had plans, ideas and the intelligence to get them seen too. Jacowitz's reputation grew, as did it's protection. With the help of the Doctor, Laksmono built a psychic amplifier to increase the strength of the planet's protective psychic layer.
He also built the Imperial Palace. His rein was shortened, however, by his untimely death at the hands of the Terileptils.
The Seventh Age - Queen Ariella
The most successful ruler to date. Queen Ariella was the first female ruler of the planet, and had the longest rein. During her rein, the Sontaran's stopped their attack, which, since the days of their creation had happened once every 5000 years. Ariella brought peace, not only to her planet, but to her galaxy. She survived thirty assasination attempts and 400 attempts at alien invasion.
The Eighth Age - King Ezekiel
During the rein of King Ezekiel, the Nyklus had their first contact with Humans as the Fourth Great and Bountiful Human Empire expanded, spreading close enough to require the help of the Nyklus for certain plants and animals.
Main Article: Nyklus
Jacowitz is said to be 500 times more beautiful than the most beautiful parts of Earth. The planet as a whole resembles Earth, but the temperature is usually a lot warmer.Winter in Jacowitz is said to be the Doctor's favourite season on any planet.