Who will be valued above Nuremberg:

The Spanish King in Capricorn thin,

Deceived and betrayed by the great Wittenberg.

As a possible suggest the following interpretation of this quatrain. The first two lines can be about Prince Henry of Prussia (1726-1802) – an outstanding commander. During the war for the Bavarian inheritance, he led the army. The result of the war was the annexation of Bavaria to Prussia, and Nuremberg – one of the largest Bavarian cities conquered by Prussia. Prince took part with the Seven Years War (1756 -1763) and won it last battle. Henry was buried in a pyramidal tomb.

The third line may be about the loss of Spain of vast territories Florida, which were transferred to England following the Paris Peace Treaty. By the way, it was signed in 1763 on February 10 (Constellation Capricorn). In exchange, Spain received Havana.

The explanation for the last line could not be found.

Probable decoding of number 6.15. If 1 is put at the ahead and consider as 1000, flip 6 in 9, 1000-915=085, flip 5 in 2, 08 swap 80 then we will get 802 – the year of death.

Quatrain 6.30 The Belgian revolution

Par l'apparence de saincte saincteté,

Sera trahy aux ennemis le siege,

Nuict qu'on cuidoit dormir en seureté,

Pres de Braban marcheront ceux du Liege.

Through the appearance of the feigned sanctity,

The siege will be betrayed to the enemies:

In the night when they trusted to sleep in safety,

Near Brabant will march those of Liege.