A Russian and Slavic form of Alexios, from Greek meaning defender or helper.
Aleksei is the Russian and Ukrainian transliteration of a name with ancient Greek roots: Alexios, derived from the verb "alexein," meaning to defend or to help. The name entered the Slavic world through the Greek Orthodox Church and the influence of Byzantine Christianity, carried by missionaries and saints into Eastern Europe from roughly the ninth century onward. Saint Alexius of Rome, a fifth-century ascetic who reportedly abandoned wealth and nobility to live as a beggar, was among the earliest prominent bearers, and his story spread widely through medieval hagiography.
In Russian imperial history, the name Aleksei became closely associated with the Romanov dynasty. Alexei Mikhailovich, known as Alexis the Quietest, was the seventeenth-century tsar whose long reign shaped Russian autocracy before the reforms of his son Peter the Great. Centuries later, Tsarevich Aleksei Nikolaevich — the hemophiliac son of Nicholas II — became one of the most famous and tragic bearers of the name, his illness and the circumstances surrounding his death in 1918 woven permanently into the history of the Russian Revolution.
Today Aleksei remains a common and beloved given name throughout Russia, Ukraine, and other Slavic countries. Its transliteration in Western contexts varies widely — Alexei, Aleksey, Alexey — with Aleksei being the spelling closest to the Cyrillic original. The name carries associations with intellect, steadiness, and cultural depth, and its spread into non-Slavic communities reflects both diaspora and a broader appreciation for Eastern European naming traditions.