Dronid

Dronid was a Gallifreyan colony. Its name should have been Drornid but there was a typo in a first edition of Bartholomew's Planetary Gazetteer so the rest of the universe (except the natives of Drornid) called it Dronid.

History
When a schism developed in the Time Lords' College of Cardinals, Cardinal Thorac declared himself Lord President and set up his own High Council on the planet Drornid. He put together an army with the hopes of overthrowing the Gallifreyan High Council. Thorac ruled Drornid from a massive statue of himself; his court was within the statue, and from the statue he transmitted a pacification beam which kept the local population happy and quiet. (PROSE: Shada, Alien Bodies)

The Time Lords on Gallifrey dealt with this rival President by ignoring him. (PROSE: Shada) Eventually Thorac was dragged back to Gallifrey, leaving a lot of Gallifreyan time technology still on the planet. (PROSE: Alien Bodies)

Faction Paradox established a base on the planet, which the Time Lords, perceiving it as a threat, attacked. Members of Faction Paradox moved en masse back to the Eleven-Day Empire. (PROSE: The Book of the War)

When the pacification beam was turned off, the inhabitants of Drornid suffered massive psychic shock, and the planet was thrown into chaos.

Thousands of years later, Drornid recovered from the trauma of Thorac's reign and its aftermath, and became the "top holiday destination of Galactic Quadrant 5". Its primary export was beachwear, and its primary import was ice cream; the past had been largely forgotten. Skagra was a native of Drornid, but disdained its sybaritic ethos.

After the Fourth Doctor defeated Skagra's plan to develop the Universal Mind, he brought Skagra's sphere to Drornid and had the locals, who were experts in genetic engineering, create new bodies for the minds Skagra had stolen. (PROSE: Shada)

Dronid was well known for its warp-poets. (PROSE: The Tomorrow Windows)

The first battle of the Second War in Heaven took place on Dronid. The Enemy attempted to set up their own Web of Time opposing the one created by the Time Lords. The Time Lords attacked the planet, destroying the surface with a virus. A future version of the Doctor died fighting there. (PROSE: The Book of the War, Alien Bodies)

In 15414, the Time Lords introduced the clockwork bacteria disease to Dronid. (PROSE: Alien Bodies)

Behind the scenes

 * Drornid was first mentioned in the script for the uncompleted serial Shada. This is also where the skeleton of the story about a schism in the College of Cardinals and the rival Presidency originates. In the 1992 reference work The Universal Databank, the planet's name was listed as Dronid; it was subsequently used in other works, including Alien Bodies by Lawrence Miles. However, Miles also acknowledged the "Drornid" spelling with a character's offhand remark. Lance Parkin later explained that "the joke that Lawrence is making is that so many people read the 'guidebook' without checking the facts that the name 'Dronid' stuck in the end!"
 * The reference book The Discontinuity Guide speculates, based on his knowledge of Gallifrey, that Dastari hailed from Dronid or Minyos (TV: Underworld).