The Imperial Templars are a Loyalist Third Founding Space Marines Chapter derived from the Black Templars' gene-seed. The Imperial Templars origin can't be traced so their existence could be kept a secret. But since their creation they have been on many crusades, most on their own and some with the Black Templars. Like the Black Templars, the Imperial Templars are not Codex Astartes-compliant Chapter and maintain a very different Chapter structure and culture than what is considered the norm in most Astartes Chapters.
High Marshall Vorus is the chapter master for the Imperial Templars. Not much is known about High Marshall Vorus due to the information from him has been lost deep in the archives. But some information is known about him.
Before becoming the first High Marshall of the Imperial Templars, Vorus was a Sword Brethren in the Black Templars. Vorus was the best fighter in his Crusade Company. During a battle Vorus's Marshall was killed and Vorus was going to be the new Marshall, but someone (who also wanted to be Marshall) claimed that Vorus was tainted by Chaos. So the Company Chaplin put Vorus under investigation but found nothing and it was too late and another Marshall was selected. So Vorus went off with some other Black Templars and created the Imperial Templars
The Imperial Templars tend to use Sword Brethren & Assault Squads as their main fighting force. They do this to stay as mobile as possible and as deadly as possible. This is achieved by the Assault Squads use of Jump packs.
Sword Brethren Squads
The Sword Brethrens are the most senior warriors in the Imperial Templars as they have seen numerous crusades and have mastered close combat. They are the elite warriors that most strive to become. Sword Brethren warriors use the finest armor weapons there is. Sword Brethrens usually spend time practicing their close combat skills with each other, or do religious traditions with a Chaplin.
Assault squads are used to weaken enemy strongholds by repeatedly charging them, or to disrupt and distract enemy units for the Initiates or even the Sword Brethrens to finish off. The Assault Squads favor jump packs with pistols and swords to ensure they survive at close combat and assaults. Assault Squads like to find new ways to strike fear into the enemy.
The imperial Templars like use pin-point assaults and hand-to-hand combat as their main tactics on their crusades. They choose these tactics because they can charge fast and hard in order for the enemy to loose moral and to not fight making it easier for them to progress on their crusades.