Hi Pedro,
I will try my best to provide some information about this unit:
Founded in 1675 they became the Guard in 1713 when their commander Frederik William the 1rst became King of Prussia. Even before that time he had started to select tall men for this unit. By then Grenadiers of the "King´s Regiment" should be no less than 1,88 m tall! Frederik William collected tall men throughout Europe and although he was quite close-fisted about expenses he spent a lot of money for his beloved giants.
Although he became known as the "Soldier-King" he never waged war and therefore his Guard did not see action. There are discussions if some of the giants would have been fit for action at war at all - one member was 2,17m tall - and their tall size could be seen as a disease with bad impact on the physical ability of the soldiers. Whatever - we never know.
His son Frederik the 2nd - the Great - disbanded this unit and reorganized them. Some soldiers were transferred into the new Prussian Guard Regiment No. 15 which saw action in the conflict between Prussia and Austria 1745 and later.
Cheers, Martin