The question of when Spain took over the Holy Roman Empire is actually a bit of a misnomer, as Spain never fully took over the Holy Roman Empire in the sense of complete domination or unification.
The Holy Roman Empire, which existed from 800 until 1806, was a complex political entity that encompassed large parts of Central Europe. While Spain, particularly during the time of the Habsburgs, held significant influence within the Empire, it did not exercise direct control over it.
In the early 16th century, the Habsburg family produced both the King of Spain and the Holy Roman Emperor, with Charles V being a notable figure as he ruled over both realms simultaneously. His reign from 1519 to 1556 marked a period of significant Spanish power within the Empire, but it was more of a personal union rather than a direct takeover.
Upon the abdication of Charles V, the Habsburg territories became divided. His son, Philip II of Spain, ruled Spain, while Ferdinand I took the title of Holy Roman Emperor. This division illustrates that although Spain had influence, it was one of many powerful states within a larger framework of politics and territories in Europe.
In summary, Spain did not take over the Holy Roman Empire in a traditional sense, but had a period of strong influence during the 16th century through the Habsburg connections. The Empire itself remained a unique and separate entity until its dissolution in the early 19th century.