The Papal Inquisition was formally established in 1231–1233 A.D. under Pope Gregory IX as a centralized system to investigate and suppress heresy within territories influenced by medieval Church authority.

Within certain historicist and Sabbatarian interpretations, it is also asserted that the number one  cause of persecution was that some believers refused to recognize the authority of the Roman Church and Empire to alter sacred observances—particularly the change of the Sabbath from the seventh day to the first day of the week. In this view, those who maintained seventh-day observance were among groups labeled as heretical and became targets of suppression.

It is important to note, however, that mainstream historical scholarship identifies multiple causes for the Inquisition, including:

• Doctrinal disputes, (specifically the changing of God's Sabbath Day)
• Challenges to ecclesiastical authority 
• Social and political instability 
• Efforts to enforce religious uniformity (Sunday rather than the true Sabbath) 

There is no single universally accepted “end date” for inquisitorial institutions, because they evolved and changed form over centuries. However, within historicist prophetic interpretation, the broader era of papal dominance is often connected to a symbolic 1,260-year period.

This prophetic span is expressed in Scripture as:

• 42 months 
• 1,260 days 
• time, times, and half a time 

Revelation 13:5 (KJV)

“And there was given unto him a mouth speaking great things and blasphemies; and power was given unto him to continue forty and two months.”
 

Revelation 12:6 (KJV)

“And the woman fled into the wilderness, where she hath a place prepared of God, that they should feed her there a thousand two hundred and threescore days.”
 

Daniel 7:25 (KJV)

“…and they shall be given into his hand until a time and times and the dividing of time.”
 

Under the prophetic day-for-a-year principle, these represent 1,260 literal years.

Historicist interpretation applies the biblical principle that in prophetic contexts, a day symbolizes a year.

Numbers 14:34 (KJV)

“After the number of the days in which ye searched the land, even forty days, each day for a year…”
 

Ezekiel 4:6 (KJV)

“…I have appointed thee each day for a year.”
 

Thus:

• 1,260 prophetic days = 1,260 literal years 

Within historicist interpretation, the 1,260-year era (538–1798 A.D.) is often understood as the prophetic Great Tribulation, marked by persecution, oppression, and martyrdom of believers.

Yeshua warned:

Matthew 24:21 (KJV)

“For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.”
 

This is connected with:

Daniel 7:21 (KJV)

“I beheld, and the same horn made war with the saints, and prevailed against them;”
 

Revelation 13:7 (KJV)

“And it was given unto him to make war with the saints, and to overcome them…”
 

Revelation 6:9–10 (KJV)

“I saw under the altar the souls of them that were slain for the word of God…”
 

There is no universally accepted exact number of those executed during the Papal Inquisition and related persecutions.

Scholarly consensus suggests:

• Although an exact number is impossible to know, it is suspected to be in the Millions that were executed directly 
• Tens of thousands or more affected in broader persecutions 

Revelation 17:6 (KJV)

“And I saw the woman drunken with the blood of the saints, and with the blood of the martyrs of Yeshua…”
 

Those condemned as heretics often suffered:

• Burning at the stake 
• Hanging 
• Beheading 
• Boiling in oil 
• Imprisonment for life 
• Confiscation of property 
• Forced labor 
• Public torture during interrogation 

In 1798, forces under Napoleon Bonaparte entered Rome, declared a republic, and took Pope Pius VI prisoner.

This is viewed in historicist interpretation as the end of the 1,260-year period.

Revelation 13:3 (KJV)

“And I saw one of his heads as it were wounded to death…”
 

In 1929, the Lateran Treaty established Vatican City as an independent state.

Revelation 13:3 (KJV)

“…and his deadly wound was healed…”
 

• 538 A.D. — beginning of papal supremacy (historicist interpretation) 
• 1231–1233 A.D. — Papal Inquisition established 
• 538–1798 A.D. — 1,260-year tribulation period 
• 1798 A.D. — Papal power wounded 
• 1929 A.D. — Vatican sovereignty restored 

Within historicist theology, the Papal Inquisition is viewed as part of a prolonged prophetic tribulation period.

The added perspective that persecution included those who rejected changes to the Sabbath reflects a specific doctrinal fact, while broader historical evidence shows multiple overlapping causes for the Inquisition.

Together, these elements form both a historical record and a theological framework through which many interpret these events.