Can somebody help me identify this story which I read in the 1980s(?).
What I remember is that in 1588 the Spanish Armada was not destroyed on its way to battle the English fleet and the English were defeated. This leads to a present 20th century in which The Spanish are the dominant culture. Technology has developed differently, with time travel but no electric light nor automobiles.
This is "Times Without Number" by John Brunner.
The Armada was successful
The book's plot takes place in the years 1988–1989 in a timeline where the Spanish Armada under the command of the Duke of Parma successfully invaded England in 1588. This success was especially due to Parma's second-in-command, the Earl of Barton – the illegitimate son of a Catholic Scottish nobleman, who entered the service of Spain and turned out to be one of the great military talents of history (at the end of the book it is explained why our history knows no such person).
Time travel technology is present in an otherwise backward society
Meanwhile, in Europe the Habsburg Monarchy transformed itself into the powerful "Confederacy of the East", ruling the whole of central and eastern Europe and becoming the long-lasting rival of the Londres-based Western Empire. In 1892, an Italian named Boromeo discovered the secret of time-travel, though otherwise the overall level of technology remained not much higher than it was in the 16th Century, with people travelling primarily on horseback and cities lit by open fires. in principle, time travel could have been used as a means of instantaneous travel, but that would have involved the traveller being in two places at the same time, at least for a split second; fearing a time paradox, such use of the device was strictly forbidden.
