Titus grew up in what is now Rembrandthuis. Around 1643, Geertje Dircx was hired as his caretaker and dry nurser. In May 1649 she and Rembrandt quarreled, probably as a consequence of Rembrandt's new relationship with Hendrickje Stoffels.

At age 14, in 1655, a year of plague, Titus made a will at his father's insistence, making his father sole heir, shutting out his mother’s family. In 1656 Rembrandt “assigned” his share in the house to Titus just four weeks prior to the application for cessio bonorum.^[3] After Rembrandt's bankruptcy, Rembrandt lost the guardianship of his son and thus control over his actions. A new guardian, Louis Crayers, claimed the house in settlement of Titus’s debt.^[4] By February 1658, Rembrandt' house was sold at a foreclosure auction, and the family moved from Jodenbreestraat to more modest lodgings at Rozengracht.^[5] The authorities and his creditors were generally accommodating to Rembrandt but he could not sell anything without their knowledge. To get around this, Hendrickje and Titus set up a dummy corporation as art dealers in 1660, with Rembrandt who had board and lodging, to continue his artistic pursuits.^[6][7]

In 1661, they secured a contract for a major project at the newly completed town hall. The resulting work, The Conspiracy of Claudius Civilis, painted outside the house, was rejected by the mayors and returned to the painter within a few weeks; the surviving fragment (in Stockholm) is only a quarter of the original.^[8] When Hendrickje died in July 1663 Titus assumed a more prominent role. In 1665 he was declared adult to handle his affairs, while Rembrandt struggled with rent arrears.^[9]

Titus was the largest and preferential creditor of his father, meaning that, if Rembrandt went insolvent, Titus became the first person to be paid off, before any other creditors could step in.^[10] In 1662 one of Rembrandt's creditors went to the High Court as he didn't accept Titus had to be paid first.^[11] Isaac van Hertsbeeck lost twice and had to pay back the money he had already received to Titus, which he did in 1668.^[12] In the end it was especially Cornelis Jan Witsen who profited from the sale at the expense of Titus.^[13]

In February 1668, Titus married the daughter of a silversmith, Magdalena van Loo (1641-1669), related to his aunt in het Bildt. He moved in at her mother's house at Singel and owned quite a few paintings by Adriaen Brouwer.^[14] Titus died on 4 September 1668 and was buried three days later. Six months later, the widow gave birth to Titia.^[15] As one of Rembrandt's heirs and in the possession of his keys, Magdalena did not wish to declare herself legatee but wanted to reserve the right and [decide] later on.^[16] Titus' considerable inheritance of 12,000 guilders passed to Titia, who married in Sloten her cousin François Bijler, and died at Blauwburgwal.^[17][18]

  Media related to Titus van Rijn at Wikimedia Commons