Europeans in Algeria constituted a very considerable portion of the population from the conquest in 1830. Indeed, there were in fact more people from Spain and Portugal than from France it seems. Italians, Germans, and the Maltese also immigrated to Algeria in high numbers.
Europeans were present in Algiers in relatively large numbers from the earliet days since the conquest. Moritz Wagner and Ferencz Pulszky say that in 1839, the population of Algiers was about 28,000 of which Europeans numbered about 8000 (French troops excluded).
I have several sources claiming that according to certain censuses, such as the one apparently carried out in 1852, the European population of Algiers was numbered about 35,197 and that of the natives (which included Muslims, Jews and "negros") at 23,303. Therefore, Algiers was largely European by this time. This is very remarkable but I have no way of confirming it's truth. Duchesne, a contemporary author, also estimated that the Europeans outnumbered the natives in Algiers during the 1850s.
Thus, the article for Algiers on Wikipedia claiming that it was only in the 20th century that the Europeans became a majority in this city is clearly false if we believe these claims.
Considering how relatively enormous was the proportion of the European population in Algeria which was in fact, if we believe the facts, even greater than that of British India, one wonders whether the Europeans started arriving in hoardes only after 1830. That is, were there any Europeans in Algeria before 1830?
Do we have anything from French sources in which they estimate the progression of growth for the European population starting from 1830? Did the European population before 1830 number in hundreds or thousands? Since in 1836 already, the pied-noir population was over 14,000. Moreover, did the Europeans form a majority in Algiers after 1830 and did this also hold true for other towns such as Constantine and Oran?