The Tamarians are a technically advanced race from the Alpha Quadrant. They are often considered to be an isolationist people. This is likely to be because of difficulty in understanding their language.
They talk in metaphors and the universal translator doesn’t do well with the language.
The Tamarians have had contact with the Federation 7 times between 2260 and 2367. The meetings went on without problems, but no formal relations took place.
In 2368, they sent a signal towards Federation space. It was standard mathematical progression. This was a message that they wanted to communicate. The Federation met them here and a major diplomatic breakthrough took place. A ship was sent to El-Adrel IV. The U.S.S. Enterprise-D met up with the ship there.
The Tamarian captain, Dathon, and Captain Jean-Luc Picard met up on the planet. They communicated on the planet and this open the communication between the two.
The vessel that was encountered at the planet, El-Adrel IV was equipped with advanced shielding and weapons. They also have advance transporter technology.