Greatest King/Emperor of the 12 century - Henry II, Manuel Komnenos or Frederick Barbarossa?

[The Merling King]

Which medieval ruler had more power, resources and influence, Henry II of England / Angevin Empire, Manuel Komnenos of Byzantine Empire or Frederick Barbarossa of Italy / Holy Roman Empire?

[The Grey Wolf]

Frederick Barbarossa?

[Spockydog]

The Kurgan.

[Zorral]

Genghis Khan ( 1155 – c. 1162 – August 18, 1227), the founder and first Great Khan and Emperor of the Mongol Empire, which became the largest contiguous empire in history after his death.

[Feologild]

Henry II

[kiko]

6 hours ago, Feologild said:

Henry II

Why?

[Galactus]

Muhammed Ghori or Suryavarman II are strong contenders 

[Knight Of Winter]

You're asking about powerful rulers of the 12th century, yet limit yourself to only three pretty euro-centric choices, neither of whom rises any close to any claim of "most powerful of the 12th century". The thing is, European countries of the 12th century were far from the most advanced in the world - neither technologically, nor scientifically, nor economically, nor societally, nor culturally nor in any other way - and that applies both to Holy Roman Empire and England. It would not apply to Byzantine Empire of the past, but by the time of Manuel Komnenos, it was slowly but surely entering its vestigial phase. Manuel in particular, while overall able and smart ruler, had very limited success dealing with Seljuk Turks in Anatolia or Normans in southern Italy.

So who would the the most powerful ruler of the 12th century? It's a good question, and while I don't know the answer - I'd suggest looking in places other than Europe. How about whoever ruled China, for example? I don't remember if China of that period was politically divided or not, but even if it was, they were still technological, military and cultural powerhouse.

Or how about Genghis Khan, who should be the most obvious choice? True, he did his conquest in the 13th century (so technically he doesn't fit your question), but in 12th century he managed to carefully and methodically lay foundations to what would become by far the largest empire in the history of humanity up to that point.

What about Saladin, for that matter, who managed to unite Egypt and Syria into a most powerful Muslim state in the last century?

Or whoever ruler the Khmer Empire, which was IIRC at the height at that time? At its peak, its capital of Angkor Wat had a population of around 1 million people, making it - maybe - the largest city in the world. Which tells you something about the size and power of their empire.

Or about countries in central Asia or Indian subcontinent? There's just bound to be someone very powerful among them.

Etc. etc.

[Zorral]

41 minutes ago, Knight Of Winter said:

Or how about Genghis Khan, who should be the most obvious choice? True, he did his conquest in the 13th century (so technically he doesn't fit your question), but in 12th century he managed to carefully and methodically lay foundations to what would become by far the largest empire in the history of humanity up to that point.

Genghis Khan is nominated already, above.  Along with his dates.  He certainly qualified.  His empire lasted longer than Harry 2's, though his sons were at least as quarrelsome . . . .

 

[IheartIheartTesla]

2 hours ago, Knight Of Winter said:

Or about countries in central Asia or Indian subcontinent? There's just bound to be someone very powerful among them.

Etc. etc.

This was right around the point in the Indian subcontinent (or to be more accurate, what is now current day India) where princely rule was very fragmented, allowing the Delhi sultanate and eventually the Mughal empire to take hold over much of the country. Galactus already mentioned Ghori, who was the catalyst for all of that.

[Clueless Northman]

In Europe, I'd go for Barbarossa. Not sure anyone else would qualify, except possibly Philippe Auguste; Henry II or Bela III probably don't compare. And then we should probably consider the Almohads (Al-Mumin or Al-Mansur). To the East, Saladin indeed is worth mentioning.

Farther East, the Ghurids hadn't yet been destroyed, so they qualify. Then either Suryavarman II or Jayavarman VII from Angkor (probably a tie between them), possibly Sithu from Bagan. China's Song got beaten badly, so I'd rather consider Taizong from Jin, who actually beat down the Song. Just like them, Srivijaya was already massively downsized in Indonesia, so that one's out.

I would pick Temujin for the 13th century. Before 1200, he didn't rule over much area and that many people and warriors. And even then, even though Genghis was the most successful by far, if we actually look at global prosperity and power and not at personal achievements, Ogodei, Mongke and possibly even Kublai would top him.

In the Americas, it seems things were badly divided at the time. Possibly not even the Chimu might have had a vast and powerful state that would qualify.

[CommonSwindler]

Without a shadow of a doubt: Henry II
 

In his heyday, Henry was the most illustrious ruler in Europe, ruling a vast collection of territories and commanding resources that far exceeded anything Barbarossa or Philip Augustus could practically command, in terms of government and administration. Due to his reforms, he was able to average revenues £40-48,000 (~$2 billion today) per annum by the later years of his reign, which far outstretched those of Barbarossa and even Manuel Komnenos. Emperors and Popes sued to him for arbitration in the great diplomatic issues of the day; the Patriarch of Jerusalem offered Henry the crown of Jerusalem before he did so to any other ruler, on account of his position as Europe’s most powerful elder statesman. This coupled with his absolutely crucial legal reforms which daily and directly impact the lives of no less than 35% of the population of the modern world and enabled him to rule more securely and effectively in his lands than any other European monarch mean simply that it is no contest whatsoever. 
 

See the works of W.L. Warren, Dan Jones, John Gillingham, Nicholas Vincent, and David Carpenter (to name but a few) for further reading.