I came across a study on the King of the North by Donn W. Leatherman of Southern called "Adventist University Adventist Interpretation of Daniel 10-12: A Diagnosis and Prescription". Its very good on how Adventist have been struggling with this issue, here is what he writes:
"The “king of the south” is understood to refer to the nation of Egypt. The “king of the north” was whatever power controlled the area north of Palestine, which, by the end of Daniel 11, was understood to be the Ottoman Empire. These interpreters expected the culmination of human history and the return of Christ to occur when Turkey, having failed in its attempts to reestablish control over Egypt, and beset by enemies from the North and East (possibly Russia and Persia), removed its capital from Istanbul to Jerusalem.
Foremost among the exponents of this interpretation wasUriah Smith, whose Thoughts Critical and Practical on the Book of Daniel, published in 1881, had extensive influence on subsequent generations of Adventists. Later editions of his works, which combined his book on Daniel with a similar volume on the Revelation, are less specific regarding the interpretation of the latter part of Daniel 11. This is particularly true of the editions printed after Smith's death. These later editions state that “the prophecy of verse 45 centers in that power known as the king of the north. It is the power that shall hold the territory possessed originally by the king of the north.”2 Clearly, after the demise of the Ottoman Empire, Smith's original interpretation seemed dubious.
Another Adventist, who had adopted views similar to those of Smith, was Stephen N. Haskell,3 the popularity of whose volume on Daniel rivaled that of Smith's work for some time after its publication in 1901. Other Adventist books expressing similar views include those of J. Grant Lamson (1909),4 Max Hill (1915),5 and O. A. Johnson (1919).6 One might have expected this interpretive tradition, especially the parts involving Turkey, to have died with the Ottoman Empire, but it persisted in the anonymous Two Great Prophecies (1925),7 and the works of M. H. Brown (1926)8 and W. H. Wakeham (1930),9 and even after
the Second World War in the works of E. A. Nixon (1945)10 and Walter E. Straw (1947).11 Without attempting to exegete the book of Daniel, other Adventist writers from this era reflected similar views in their works. These include Alonzo T. Jones (1900)12 and Arthur G. Daniels (1917).
After World War II many interpreters adopted a more radical revision of the earlier position represented by Uriah Smith, Stephen Haskell, and the great majority of Adventist writers of the early twentieth century. Beginning with Edwin R. Thiele,19 some Adventists identified Rome not only in verses 14 through 35, but in the last 10 verses of the chapter as well. Thiele's explanations of the last 6 verses of the chapter are somewhat vague historically, but nevertheless apply this passage to the papacy without hesitation.20 Thiele also differs from earlier interpreters in applying vss. 29-30 to the Crusades and the medieval church, rather than to the sack of Rome by the barbarian kingdoms.21 Thus Thiele's interpretation of Daniel 11:29-45 has a somewhat later historical framework and omits reference to the French revolution and to the Ottoman Empire. A similar position was adopted by Louis Were in 1949.22 Were makes no attempt to exegete the entire chapter; his focus is more narrow, but he does assert that the references to literal (i.e., pagan) Rome end in Daniel 11:30, and that vss.31-45 describe spiritual Rome.23 References to the “king of the north” in this part of the prophecy point to the papacy:
The power brought to view in Dan. 11:40-45 must be one whose activities concern the people of God—such has been Daniel's previouspresentations of the work of the papacy.24
In a 1955 publication, George McCready Price returned to the essential position of Uriah Smith regarding the interpretation of Daniel 11:29-32, but accepted the views of later interpreters who applied vss. 36-39 to the papacy. Price denies emphatically that these verses can be made to refer to revolutionary France.25 Furthermore, the last six verses of the chapter are also held to describe the demise of the papacy. Egypt, the king of the south, represents atheistic science. Price acknowledges two possible scenarios: one in which there are two major actors (the “king of the north” and the “king of the south”) and another in which there are three major actors, with the third person pronouns of verses 40 to 45 refer to some other entity. The differences between these interpretations Price holds to be slight, since “both views agree in saying that the main world power dealt with here is the Roman papacy, . . .”26
The last three verses of the chapter receive only brief comments. Price denies that the geographic references should be literally understood, states that parts of the passage are yet unfulfilled, and encourages the reader to wait until these passages are clarified by unfolding events before insisting on a specific interpretation.27
Robert Brinsmead (1960) concurs in the identification of the “king of the north” with the papal system and the “king of the south” with atheism.28 He sees in the final verses of Daniel 11 a conflict between two opposing ideologies —Babylonian and Egyptian. . . . Babylonian is to profess to be a Christian, to have a form of godliness, but to deny the power thereof. Egyptian is to repudiate the Christian religion and to deny the very existence of God.29 Clearly, the major focus of the closing verses of Daniel 11 in this interpretation is still on the demise of the papacy.
The Seventh-day Adventist Bible Commentary declines to speak decisively on this passage. In verse after verse the reader is presented with tentative speculation (“Some see specific reference here . . .”) or alternative and mutually contradictory views (“Others suggest . . .”).30 The editors suggest two possible interpretations of verse 40: that the “king of the north” is Turkey, and that the “king of the north” is the papacy.31 No comment is offered on vss. 41-44, and the comment on vs. 45 consists primarily of a warning from James White to be cautious in offering interpretations of unfulfilled prophecy.32
The view that the “king of the north” represents the papacy and that the final portion of Daniel 11 describes the eschatological demise of papal power is also supported (though with important differences in interpretation) by both Desmond Ford (1978) and Mervyn Maxwell (1981). Ford applies Daniel 11:29,30 to the evacuation of Antiochus IV from Egypt at the command of the Roman Senate. In subsequent passages he sees intimations of both the Antiochene desecration of the Jerusalem temple and the anti-Jewish and anti-Christian activities of Rome. Thus Ford holds the possibility for multiple fulfillmentsof these passages...Ford applies vss. 36-39 to the papacy, but is reluctant to be very specific on vss. 40-45. He remarks that at this point “we . . . enter upon delicate ground, as this is obviously in the realm of unfulfilled prophecy.” He does insist (against Price and Bunch) that there are only two powers, not three, in the conflict describedin these verses.34 He associates the “king of the south” with atheism, or “some latter-day movement opposed to religion.”35
Maxwell, whose interpretations are significantly closer to Adventist tradition, associates all of Daniel 11:29-45 with the papacy, specifically identifying the last six verses of the chapter with the “demise of Roman Christianity.”36 Nevertheless, he is considerably less specific in his interpretation of this passage than in his treatment of earlier chapters, or even of earlier parts of this chapter. He gives a detailed verse-by-verse interpretation of Daniel 11: 1-16. His comments on subsequent verses are more general, and are not always in canonical
order.37...."Adventist Interpretation of Daniel 10-12: A Diagnosis and Prescription https://digitalcommons.andrews.edu/jats/vol7/iss1/7
The world is not governed by kings any longer; the king of the north symbolizes geopolitical powers at play in world history. Daniel looks through the history of time and point us to the end-times and says,
40And at the time of the end shall the king of the south push at him: and the king of the north shall come against him like a whirlwind, with chariots, and with horsemen, and with many ships; and he shall enter into the countries, and shall overflow and pass over….
Obviously, this end-time king of the north will a powerful military force capable of moving its military forces at will. The bible points us to a power which has existed in some form or another in the past and says it will also exist in the end-time.
8The beast that you saw— it was, and now is no more, but is about to come up out of the Abyss and go to its destruction….(...he shall come to his end, and none shall help him.)
Today on the world’s geopolitical scene we see a country whom the world has considered to be leader of the free world giving up that mantle to the point where nations are questioning its future role in the world. In a 12 Sept. article from the EU Observer reads.
European Commission president Jean-Claude Juncker said Europe needs to show more leadership in the Trump-era, where American power is retreating from the world stage.
Some people believe this European power is the king of the north, no matter what form it may take in the future as Revelation 17 point out:
…12The ten horns you saw are ten kings who have not yet received a kingdom, but will receive one hour of authority as kings, along with the beast. 13These kings have one purpose: to yield their power and authority to the beast.
So, will it be this European Union that will be the king of the north as some believe? We’ll have to wait and see.