Karl Ivanovich Blank (1728, 1793) was a Moscow architect and construction engineer, known as one of the last masters of baroque and the first architect of early classicism. He became famous for his temple constructions, such as the Trinity Church in Serebryaniki and the Church of Nicholas in Zvonyari, as well as the building of the Educational House on the Moskva River embankment. Karl was the son of architect I. Ya. Blank.

His family descended from French Huguenots who once fled to Germany. Karl's grandfather, Yakov, was a blacksmith who came to the Olonets factory under Peter I. His father, Ivan Yakovlevich, started as a translator for German architects in St. Petersburg and later became an architect and assistant to P. M. Yeropkin.

In 1740, Yeropkin was executed in the case of A. P. Volynsky, and I. Ya. Blank was sentenced to be whipped and exiled to Siberia for life with his family. Karl's mother died on the way. After arriving in Tobolsk, a coup occurred in St. Petersburg, and the family was allowed to return to Moscow. In Tobolsk, Karl met A. F. Kokorin, who became a student of I. Ya. Blank and went with them to Moscow.

Ivan Yakovlevich soon died after their return, and Karl Blank, along with Alexander Kokorin, continued working in the construction teams of I. K. Korobov and P. Obukhov. In 1749, Karl passed the exam for the title of architecture gezel at Rastrelli and became an assistant to A. P. Yevlashev. At Rastrelli's initiative, he worked on the project to restore the Resurrection Cathedral of the New Jerusalem Monastery, but this project was not realized. Only in 1756 and 1759 did Blank lead the reconstruction of New Jerusalem. Early works by Blank, such as the Moscow Annenhof, have not survived.

In the 1760s, during the peak of his creativity, Blank designed the city for the coronation of Catherine II. He lived on Rozhdestvenka, where he became the house architect of Count I. L. Vorontsov. Here he built the Church of Nicholas the Wonderworker in Zvonyari and the Spasskaya Church in Voronovo. He also constructed the Church of the Life-Giving Trinity in Serebryaniki, the Church of the Great Martyr Catherine on Vspolye, the Church of Boris and Gleb on Arbat Square, and the Church of Kyra and John on Solyanka.

Some researchers attribute to Blank the design of the estate church in the estate of Troitskoye-Kainardzhi, based on the mention of his surname in the correspondence of the Rumyantsevs. However, his role could have varied from architect to consultant.

In 1764 and 1781, Blank built his largest project, the Moscow Educational House, which became an important milestone in architecture, marking the transition from baroque to classicism. Its strict facades seemed ascetic for that time, and only a quarter of a century later did the classical style become dominant in Russia.

During those years, Blank participated in major construction projects, such as the Catherine Palace and the Senate Palace in the Kremlin. However, he was removed from the design of the Senate, and the project was handed over to M. F. Kazakov. Until the end of his life, Blank remained in demand by private clients, consulting, for example, P. B. Sheremetev during the construction of the Kuskovo Palace and creating a greenhouse, "Hermitage" and "Dutch House" there.

Blank had five children, among his descendants were Decembrist N. V. Basargin and P. P. Semyonov-Tyan-Shansky. He passed away on October 26, 1793, in Moscow at the age of 65.