In fact the medieval settlement of Belfast was roughly a block farther south - the castle was roughly on Castle Lane, and what settlements there were around it appear to have been on Anne Street - although the oldest church in Belfast is generally described as being sited on High Street, its original entrance was from Anne Street. This is because that axis was the centre of a spit of land between the Farset River (now High Street) to the north and the original course of the Blackstaff (roughly Donegall Square North / Chichester Street / Victoria Square) to the south, leading from the castle to the original ford or causeway across the Lagan which was fairly close to where the Queen's Bridge is now.
The castle lay at the boundary between different Gaelic chieftains' territories, and was never held by anyone for very long. The Earl of Essex proposed settling it as a town in the 1570s but died horribly. Eventually the Chichester family, who became the Earls of Donegall (sic), took it on and rapidly developed the town in the first decades of the seventeenth century.
Here I expected that we would switch back into the narrative I learned at school of a development centred around High Street. But I was out by a block again, though in the other direction this time: the seventeenth-century town took Waring Street as its principal axis, though the church remained on the southern shore of High Street, on (or even off) the edge of town. The Donegalls developed a new castle on the site of the old one, but it was for ostentation rather than defence, and they preferred to have the townsfolk living at arms length, farther north.
The next major development came with the conflict of the 1640s. In 1641, the largely Protestant townsfolk managed to fight off Catholic insurgents and became a haven for displaced refugees from elsewhere in Ulster. The town's defensive ramparts were built in 1642, but Belfast changed hands several times over the next few years between Royalist, Parliamentarian and Scottish forces, so the ramparts probably weren't much use (Gillespie suggests they were badly designed and the maps show clearly that they left a large gap at the northern edge of town).
Over the second half of the seventeenth century Belfast thrived, as the local political situation settled down (King Billy passed through in 1690). But partly as a result of the forced population movements of 1641, it had become the most militantly Presbyterian town in Ireland, and this made for unhappy cohabitation with the Donegalls. The economy slumped in the eighteenth century, and Belfast was hit particularly badly. the Donegalls were unable to provide leadership (the third earl was killed fighting in Spain in 1706, his son who lived to 1757 apparently had a learning disability, and the family became less fond of Belfast after the earl's three daughters were killed when the castle burned to the ground in 1708. Although the Donegalls fought and won their battles with the (mainly Presbyterian) merchants for political domination of the town, the legacy was one where the landlords were not really disposed to foster the local economy. Again, returning to my schoolbook, the story of Belfast starts to pick up with the linen trade in the later eighteenth century, but really this could have happened fifty years earlier if the Donegalls and merchants had come to terms. The fifth earl / first marquess was prepared to forgive and forget, and started the great push of development after 1757.
I was really struck by the similarities between the early histories of Belfast and New Amsterdam / New York. Belfast was founded about fifteen years earlier, but equally as part of a colonisation project, and both found themselves, after a few decades of development, playing rather marginal roles in the geopolitical conflicts of the mid to late sixteenth century. (The Belfast defensive rampart of 1642 was as militarily useless as the wall built to protect New York in 1653.) Both are well-situated on usable harbours at the natural confluence of trading routes into their respective hinterland. But a century after their foundation, Belfast was slumping while New York was booming.
New Amsterdam, of course, started life as a project of the Dutch government rather than just of one family, and I suspect another factor may have been that potential settlers were more terrified of Irish Catholics than Native Americans. But even so, the two projects were developing at relatively level pegging for their first few decades (New York's population in 1646 was about 400, Belfast had 589 taxpayers in 1660 so it population must have been several times bigger). The real difference is that Belfast remained a family fiefdom - the Donegalls were on the winning side of all the seventeenth century wars, apart from a brief interlude in the 1640s - while New Amsterdam was captured by the British, who then had to come to terms with the population - who accepted the rebranding of the city as "New York" but held onto (and indeed strengthened) various cultural and religious rights not enjoyed at the mouth of the Farset. All very thought-provoking.