The Lisbon Meridian

The equator's position is fixed and determined by geography and mathematics. The prime meridian's position is not only not fixed, it's utterly arbitrary. It took until 1851 for most of the world to establish the Greenwich meridian as their standard, and several nations (France most notably, but also the Empire of Brazil) didn't accept it for decades.

Andalusada, ever the disorganized one, has reduced its own mess of meridians to three. And unlike IRL, the dominant one is based not in England-Scotland but in Lisbon.

Origins of the Lisbon Meridian

The Portuguese Empire was the first global empire, and for a fairly long time it was also the only one. (Moorish Spain was tied up consolidating its control in Africa. [details?]) Cartography was important to them, and the IRL Mercator projection is known locally as the Silvanian projection (after its founder, Paulo Afonso da Silva.) Unsurprisingly, he centered the map on Lisbon, such that the entire Portuguese Empire could be defined in relation to it.

• Gonzalan friars introduced the projection to the Takasagonese, for instance.

The Great Realignment screwed the Iberian powers, but it actually increased the popularity of the Lisbon meridian. About the same time the Moorish Civil War destroyed Umayyad Seville, the Portuguese Empire had its own civil war, which I've hinted at but never discussed in any depth or detail. What I know is that almost an entire continent broke away, declaring itself the Grand Principality of Cabralia. At a stroke, the number of nations using the Lisbon meridian doubled.

• When the Second Balthazarist War led to the breakaway of the CRC, the number of Cabralian nations using the Lisbon meridian rose from one to four - and, given the nature of the CRC, just kept climbing.

The three meridians

Standardization, of course, doesn't just happen; it needs a catalyst. That catalyst came in the form of Saxony, who convened a conference for the sake of establishing a world standard. [details?] doesn't begin to cover this conference; I have no idea when or where it was, how many states participated, or what the exact goings-on were. All I'm really certain of is that Saxony was pushing the Lisbon meridian, for a few basic reasons:

• The Portuguese Empire was still world-spanning, and the Lisbon meridian was more commonly known outside the West than any other.
• Almost independent state in the New World (at least the ones with a merchant marine) used the Lisbon meridian. (So did a lot of the dependent states, courtesy of the CRC.) Thus, while the largest fleets by tonnage didn't use it, the most did.
• The unspoken reason for Saxony's pushing of the Lisbon meridian was that the Portugese Empire was one in serious decline. Even if the world standardized on Lisbon, the world was never going to centralize on it.

It was universally adopted, with two major exceptions: England-Scotland and France, for more or less the same reasons: they had world-spanning empires, large mercantile fleets, and a vested interest in making the world revolve around them.