alternatehistory.com

While this is a very unplausible idea, I don't think it is ASBish.

The Treaty of Tordesillas was agreed upon by the Spanish and the Portuguese to clear up confusion on newly claimed lands in the New World. On May 4, 1493 Pope Alexander VI (Spanish) took action to clear up confusion that had arisen over territorial claims. He issued a decree which established an imaginary line running north and south through the mid-Atlantic, 100 leagues (480 km) from the Cape Verde islands. Spain would have possession of any unclaimed territories to the west of the line and Portugal would have possession of any unclaimed territory to the east of the line.

After further exploration, the Portuguese grew dissatisfied with the agreement when they realized how much more land Spain had been given. In June of 1494 the line was renegotiated and the agreement was officially ratified during a meeting in the Spanish town of Tordesillas. The Treaty of Tordesillas reestablished the line 370 leagues (1,770 km) west of the Cape Verde Islands.

Little actual exploration had taken place at the time the treaty was signed because Spain was granted a much larger portion of land. Portugal was only given possession of Brazil. Portugal pushed over the next several hundred years to move the border of Brazil westward. Because the line was not very well defined, the Spanish did not put up any opposition to this Portuguese expansion.



What if the ruling had been that Spain gains everything north of the Equator, while Portugal gains that south of the Equator?

Initially it works out to be almost the same as OTL. Little land had actually been discovered. Those lands already possessed by christian nations remain thier claims. Portugal's possessions were mostly south of the equator to begin with in the Americas. In Africa it was the same plus those areas along the Gulf of Guinea. Portugal would still be blocked from India in theory, which they would not like as per OTL.

How would these two powers change their colonial efforts with this change?
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