Which viruses still present today caused a deadly pandemic/epidemic in the past?
There are a few viruses which are around for a long time and have caused recurring episodes of disease. Most of these where not pandemic, which is probably more of a problem for modern times due to fast travel/exchange of people and are also a problem of &quot;modern&quot; cities where many people come together in a limited space.
Among theses viruses are:

Measles: This virus is around since at least 400 BC, profiting from the first big cities. (see reference 1 and 2 for more details)

Polio: This virus has been described already in ancient Egypt, although major outbreaks didn't happen before the early 20th century. There is a nice article in Wikipedia about it, see reference 3.

Smallpox: These are only not threat anymore because mankind successfully eradicated them. They have been described first around 1500BC in India, later also in China and Egypt. See reference 4 and 5.


Not viruses but also pathogens which caused historic epidemics: Typhoid fever, Cholera and the Yersinia Pestis (also known as The Plague or the Black Death).
References:

The history of measles: from a 1912 genome to an antique origin
Measles may have emerged when large cities rose, 1500 years earlier
than thought
History of Polio
Emergence and reemergence of smallpox: the need for development of a
new generation smallpox vaccine
History of Smallpox