Daniel's 70th Week
Here is an excellent article I found regarding the 70th week of Daniel and the supposed 'gap' between the 483 and 490 years.
Up until about the time of John Darby circa 1850, Christians believed the 70 weeks of Daniel had been fully completed. There was no "gap" theory.
Introduction
In looking for an answer, it often helps to review what others who came before the current time thought about the 70 weeks or 490 years of Daniel 9:24-27. This is not to say whether or not their calculations were accurate in terms of starting and ending dates, but rather it is only to answer whether they thought the 70 weeks had been completed. We will see in fact a variety of starting and ending dates in their answers; however, we will find that yes, they all thought the 70 weeks had been fulfilled in the 1st century. None were looking for some sort of temporally disconnected one week (7 years) or 3 ½ years that remained to be fulfilled. This is so up until the mid 1800’s.
The focus of this post will not attempt to address the implications for the modern believer who might be looking for some future fulfillment yet to come, but rather, simply to answer the question whether the 70 weeks of Daniel have been fulfilled or not.
Historical Review
We will consider a number of early Christians who delved into Daniel.
Julius Africanus wrote about 220 CE and influenced Eusebius and other historians. He believed that all 70 weeks had been fulfilled in Christ’s time.
It is by calculating from Artaxerxes, therefore, up to the time of Christ that the seventy weeks are made up, according to the numeration of the Jews [literal versus prophetic year]. Julius Africanus, XVI, From Fragments of the Chronography as quoted by Schaff http://www.ccel.org/ccel/schaff/anf06.v.v.xvi.html
Athanasius of Alexandria was opposed Arianism and promoted consubstantiation between God the Father, Son, and Spirit. He wrote around 350 CE. He argued that the full 70 weeks was fulfilled to answer accusations that Messiah was yet to come; some were still looking for Christ.
Perhaps with regard to the other (prophecies) they [those still expecting a future fulfillment of the 70 weeks] may be able even to find excuses and to put off what is written to a future time. But what can they say to this, or can they face it at all? Where [Daniel 9:24] not only is the Christ referred to, but He that is to be anointed is declared to be not man simply, but Holy of Holies; and Jerusalem is to stand till His coming, and thenceforth, prophet and vision cease in Israel. Athanasius, On the Incarnation of the Word, chapter 39 http://www.ccel.org/ccel/schaff/npnf204.vii.ii.xxxix.html
Tertullian wrote about 200 CE and is considered the father of Latin Christianity understood the 70 weeks as completely fulfilled by the coming of Christ and destruction of the Temple in 70 CE.
Accordingly the times must be inquired into of the predicted and future nativity of the Christ, and of His passion, and of the extermination of the city of Jerusalem, that is, its devastation. For Daniel says, that “both the holy city and the holy place are exterminated together with the coming Leader, and that the pinnacle is destroyed unto ruin.” Tertullian, An Answer to the Jews, chapter VIII http://www.ccel.org/ccel/schaff/anf03.iv.ix.viii.html
There are other early commentators such as Hippolytus, Origen, and others. Basically, regardless of their starting and even ending points, they all understood that the 70-week decree was fulfilled.
Origen circa 220 CE
The weeks of years, also, which the prophet Daniel had predicted, extending to the leadership of Christ, have been fulfilled. https://ccel.org/ccel/schaff/anf04/anf04.vi.v.v.i.html
And according to Daniel, seventy weeks were fulfilled until (the coming of) Christ the Ruler. https://ccel.org/ccel/schaff/anf04/anf04.vi.v.v.ii.html
Clement of Alexandria wrote circa 200 CE
From the captivity at Babylon, which took place in the time of Jeremiah the prophet, was fulfilled what was spoken by Daniel the prophet as follows: “Seventy weeks are determined upon thy people, and upon thy holy city, to finish the transgression, and to seal sins, and to wipe out and make reconciliation for iniquity, and to bring in everlasting righteousness, and to seal the vision and the prophet, and to anoint the Holy of Holies. Know therefore, and understand, that from the going forth of the word commanding an answer to be given, and Jerusalem to be built, to Christ the Prince, are seven weeks and sixty-two weeks; and the street shall be again built, and the wall; and the times shall be expended. And after the sixty-two weeks the anointing shall be overthrown, and judgment shall not be in him; and he shall destroy the city and the sanctuary along with the coming Prince. And they shall be destroyed in a flood, and to the end of the war shall be cut off by desolations. And he shall confirm the covenant with many for one week; and in the middle of the week the sacrifice and oblation shall be taken away; and in the holy place shall be the abomination of desolations, and until the consummation of time shall the consummation be assigned for desolation. And in the midst of the week shall he make the incense of sacrifice cease, and of the wing of destruction, even till the consummation, like the destruction of the oblation.”2071 That the temple accordingly was built in seven weeks, is evident; for it is written in Esdras. And thus Christ became King of the Jews, reigning in Jerusalem in the fulfilment of the seven weeks. And in the sixty and two weeks the whole of Judæa was quiet, and without wars. And Christ our Lord, “the Holy of Holies,” having come and fulfilled the vision and the prophecy, was anointed in His flesh by the Holy Spirit of His Father. In those “sixty and two weeks,” as the prophet said, and “in the one week,” was He Lord. The half of the week Nero held sway, and in the holy city Jerusalem placed the abomination; and in the half of the week he was taken away, and Otho, and Galba, and Vitellius. And Vespasian rose to the supreme power, and destroyed Jerusalem, and desolated the holy place. And that such are the facts of the case, is clear to him that is able to understand, as the prophet said. https://ccel.org/ccel/schaff/anf02/anf02.vi.iv.i.xxi.html
Future View
The typical starting point for when the “gap” theory between the 69th and 70th week was introduced sources to John Darby, a founder of the Plymouth Brethren. He wrote in the 1830’s. Aside from the historic view, there were others near that time, but still before him, who disagreed with Darby; they were men like Matthew Henry (c1700), John Calvin (c1550), and Sir Isaac Newton (c1700), and bibles like the Geneva Bible. They maintained the “fulfilled historic” view, rather than the “future view”.
From Matthew Henry, Commentary on the Whole Bible, Daniel Chapter IX, section III, to wit,
"1. The times [Daniel's 70 weeks] here determined are somewhat hard to be understood. In general, it is seventy weeks, that is, seventy times seven years, which makes just 490 years. The great affairs that are yet to come concerning the people of Israel, and the city of Jerusalem, will lie within the compass of these years. ... It does serve still to refute and silence the expectations of unbelievers, who will not own that Jesus is he who should come, but still look for another. This prediction [Daniel's 70 weeks] should silence them, and will condemn them; for, reckon these seventy weeks from which of the commandments to build Jerusalem we please, it is certain that they have expired above 1500 years ago; so that the Jews are for ever without excuse, who will not own that the Messiah has come when they have gone so far beyond their utmost reckoning for his coming. " http://www.ccel.org/ccel/henry/mhc4.Dan.x.html
And then there is this from John Calvin.
After the grace of Christ had been obstinately rejected, then the extension of abominations followed; that is, God overwhelmed the temple in desecration, and caused its sanctity and glory to pass utterly away. Although this vengeance did not take place immediately after the close of the last week, yet God sufficiently avenged their impious contempt of his gospel, and besides this, he shews how he had no longer need of any visible temple, as he had now dedicated the whole world to himself from east to west. http://www.ccel.org/ccel/calvin/calcom25.iv.xxxviii.html
Sir Isaac Newton also believed the 490 years were fulfilled.
For by joining the accomplishment of the vision with the expiation of sins, the 490 years are ended with the death of Christ. https://www.blueletterbible.org/Comm/newton_isaac/prophecies/daniel10.cfm
The key verse that was changed to allow the change from “fulfilled” to “future” was to whom the “he” referenced. Again, prior to Darby, no one thought the “he” referenced anyone but Messiah.
And he shall confirm the covenant with many for one week: and in the midst of the week he shall cause the sacrifice and the oblation to cease, and for the overspreading of abominations he shall make it desolate, even until the consummation, and that determined shall be poured upon the desolate. Daniel 9:27 (bold mine)
Prior to Darby, all of the writers referred the “he” to Messiah. But Darby believed it referred to the prince who destroyed the city in 70 CE or Titus or more generally the Romans. Thus he looked for some sort of revived Roman Empire consisting of 10 states (toes).
Cyrus I. Scofield picked up the new teaching and published it. Since the Scofield Reference Bible of 1917, this theory has gained in popularity. Another person who picked up the new tradition was Sir Robert Anderson who published The Coming Prince.
Conclusion
Up until about 1850, all the research points to the fulfillment of the 70 weeks of Daniel. After Darby, even though his contemporaries argued against the gap idea, the belief in a future fulfillment was popularized.