When her first husband, Henning's uncle Ben von Anstetten (Andreas Jung) is poisoned and dies, she marries murders his illegitimate son Rajan Rai (Sascha Zaglauer) to inherit his fortune, and then kidnaps Clarissa.

Tanja murders pregnant Cleo Winter (Dinah Alice Schilffarth) to cover her tracks before leaving town in 1998.

She kills Tim and escapes in 2001, returning with another plan to marry and then murder Henning (now portrayed by Patrik Fichte) to inherit his fortune.

[3]Lahnstein returned to the role from 24 April to 5 October 2001, in part to facilitate the exit from the series of Isa Jank as Clarissa von Anstetten.

[4][5] She reprised the role in the 2020–2021 TVNOW revival series, Verbotene Liebe: Next Generation, first appearing in the ninth episode on 18 January 2021.

[6][7] Bernd Peters of Bild wrote of Tanja, "For the past 20 years, the beautiful countess has only been about one thing: power, money and influence," noting that she will do anything, including murder, to get what she wants.

[7] The character has been described as cunning, manipulative and scheming,[8][9] and Tobias Dupke of Die Welt wrote that "Tanja actually embodies evil".

[10] When Tanja returns in 2004, her criminal record has been mysteriously expunged by Donald Rush (Andreas Engelmann), whom she later kills with a poisonous snake and frames someone else.

"[2] In June 1995, young blonde beauty Tanja Wittkamp comes home to Düsseldorf from boarding school to see that her parents are bankrupt and have to sell their stud farm.

Tanja disappears, but returns in 1996 as the wife of Benedikt von Anstetten (Andreas Jung), Christoph's hated brother, who agrees to help with her vendetta.

Anstetten butler George Helthay (Jochen Stern) attempts to poison Clarissa, but kills Ben instead, and Rajan inherits his fortune.

As lawyer Marc Geppard (Peter Mustafa) attempts to defraud Rajan on Tanja's behalf, she begins an affair with Tim Sander (Roland Pfaus).

[16][17] Tanja stages an attack on Marie von Beyenbach (Solveig Duda), knowing she is engaged to Henning (now portrayed by Patrik Fichte), and comes to her rescue.

Having survived the crash, Tanja returns in April 2004, her criminal record mysteriously expunged by her employer, Donald Rush (Andreas Engelmann).

She helps smuggle counterfeit money into the country as part of a business deal with Ansgar von Lahnstein (Wolfram Grandezka).

After Donald tries to kill her, Tanja murders him with a poisonous snake and frames Bernd von Beyenbach (Ron Holzschuh) for the crime.

Having acquired evidence of Ansgar's criminal liability in a spoiled baby food fiasco, she blackmails him to testify in her favor in March 2008.

[28][29] Kitty is hit by a car and killed, and witnesses Charlie and Elisabeth von Lahnstein (Martina Servatius) are led to believe they saw Nathalie behind the wheel.

[34][35] Ansgar and Nathalie try to discover Tanja's secret, which they believe is related to the mysterious death of her younger brother Thomas when they were children.

[56] Tanja demands that in exchange for their son's whereabouts, Ansgar must give her half of Lahnstein Holding and a confession on tape about his latest scheme against her, as protection.

[70][71] Tanja discovers that Ansgar has taken all of her money, just as he sleeps with his cousin Sebastian's wife, Lydia von Lahnstein (Theresa Underberg).

[96][97] Tanja is thrown when Sebastian makes a very sober proposal of marriage to her, but he rescinds it before she can answer because his issues with his father Ludwig von Lahnstein (Krystian Martinek) have sapped his confidence.

Tanja is tempted to sell her shares to an outsider in exchange for Königsbrunn Castle itself, but her feelings for Sebastian hold her back.

[100][106] Tanja devises an ad campaign for a new perfume called Incest, exploiting the story of Jan Brandner (Hubertus Grimm) and his twin sister Julia von Anstetten (Nina Bott), Clarissa's children who were separated at birth and fell in love with each other as adults.

[115] Tanja leaves for a photo shoot in Palma de Mallorca, unaware that Clarissa is there, trying to rebuild her relationships with Jan and Julia.

Tanja is accused of attempted murder, but cannot prove her innocence as the footage from the surveillance cameras is missing, stolen by Clarissa.

Sebastian donates part of his liver to Clarissa's ailing grandson Timo despite her refusal to exonerate Tanja in exchange.

[8][144] In the 2020–2021 TVNOW revival series Verbotene Liebe: Next Generation, it has been five years since Ansgar was arrested for murder, and the Lahnstein empire is crushed.

[145] Even the family's home, Königsbrunn Castle, is now owned by the Verhovens, a fashion dynasty who also acquired LCL with the help of Clarissa.

Tanja later appears and pays Clarissa's former assistant Juri Kasky (Jannik Scharmweber) for his role in her enemy's death.