A more thorough explanation:

TEMPLAR

A barrister who has chambers in the Temple of the Inns of Court. The Middle and Inner Temples are so named because they are housed in buildings on land that once belonged to the Knights Templars.

John is a templar who practices law in the Middle Temple.

Sarah's chambers are located in the Inner Temple, making her a templar.

These examples illustrate that a templar is a barrister who has chambers in the Temple of the Inns of Court. The Middle and Inner Temples are two of the four Inns of Court in London, and they are named after the Knights Templars who once owned the land. Barristers who have chambers in these buildings are referred to as templars.