Our Team of Experts

Our Team of Experts 1
Björn Maibaum

Björn Maibaum advises on legal questions involving civil and public law. After completing his law degree (specialising in European law) and a Japanese language degree, he worked as a junior lawyer for the German Chamber of Foreign Trade in Tokyo, and for the public prosecutor’s office and the district court in Wuppertal. Later, he started working as a lawyer in Köln-Lindenthal, sharing an office with lawyers Christ and Külschbach. Since 2004 he has managed the Maibaum Law Firm in Cologne.

Gunter Christ
Gunter Christ

Gunter Christ studied law at the University of Cologne and has been a practising lawyer in Cologne since 1987, specialising in immigration law. Mr. Christ is known throughout Germany as a proven specialist for Afghanistan. He has been a member of the Cologne Refugee Council since the late 1980s and part of a working group for lawyers specialising in immigration and refugee law in North Rhine-Westphalia since 1987. Since January 1998, he has also been a legal advisor to the Diocesan Caritas Association for the Archdiocese of Cologne and the German Caritas Association and, in this capacity, a member of the Legal Advisors' Conference of Lawyers Working with Welfare Organisations and the United Nations High Commissioner for Refugees (RBK). In May 2000, Mr. Christ co-founded the Working Group on Immigration and Asylum Law and was, among other things, a member of the first managing committee.

Our Team of Experts 2
Natasha Bond

Natasha Bond studied English and German law at the University of Cologne and University College London. During her studies, she was already committed to helping refugees, including at the Student Action for Refugees Society in London, where she was a member of the board. She has been a member of the Refugee Law Clinic Cologne since 2019. After her first state examination she worked for the NGO Transparency International and a law firm specialising in immigration law, gaining valuable experience for her work as a lawyer. She then successfully completed her second state examination and was admitted to the legal profession. She is a member of the German Bar Association and the Cologne Bar Association. Ms. Bond is a native German and English speaker and advises our clients competently in both languages.

Birte Windheuser
Birte Windheuser

After completing her second state examination (zweites juristisches Staatsexamen), Ms. Windheuser joined Maibaum law firm. During her university studies, she specialised in international and European law. Ms. Windheuser has a longstanding history of volunteering in the field of refugee aid and can draw on a wealth of experience. Since 2015 she has been involved in the "Welcome to Nippes" initiative in Cologne, where she advises and supports refugees. She has also worked at a psychosocial centre for refugees in Bochum. In addition to her native German, Ms. Windheuser is fluent in English and Spanish. Having completed international work assignments in Santiago de Chile, Bogotá and Bolivia and a degree in "Regional Studies Latin America", she possesses a high level of intercultural competence which is a great asset to our team.


Mrs Windheuser is a member of the German Bar Association and the Cologne Bar Association.

Our Team of Experts 3
Leonie Kämpfer

Attorney Kämpfer studied law in Freiburg im Breisgau. During her studies, she provided legal advice to individuals seeking assistance as part of her volunteer work with a student legal advisory association, where she also served on the board. During her legal clerkship in the district of the Higher Regional Court of Hamm, she worked in a department for European law in the German Bundestag in Berlin, where she further developed her expertise in cross-border cases. Since passing the second state examination and being admitted to the bar in 2021, Ms. Kämpfer has worked as a lawyer in a law firm specializing in migration law in the Cologne area. She has been part of our team at Maibaum Rechtsanwalts GmbH since June 2024.

Our Team of Experts 4
Theresa Hollerith

Attorney Hollerith studied law in Bonn and Lyon. During her studies, she dedicated herself with great commitment to supporting refugees through the Refugee Law Clinic. During her legal clerkship in the district of the Higher Regional Court of Cologne, she worked at the German Embassy in Namibia, gaining valuable experience for her career. Since passing the second state examination and being admitted to the bar in 2022, Ms. Hollerith has worked as a lawyer in a law firm specializing in migration law in the Cologne area. She has been part of our team at Maibaum Rechtsanwalts GmbH since May 2024. Ms. Hollerith advises our clients in both English and French.

Our Team of Experts 5
Ozan Atas 

Mr. Ozan Atas is a lawyer and certified specialist in migration law and social law. He studied law with a focus on asylum and social law at Bielefeld University. He completed his legal clerkship in 2016 in the district of the Higher Regional Court of Hamm and, as a legal trainee, worked at the Public Prosecutor's Office and the Regional Court of Bielefeld. He then worked at the Federal Office for Migration and Refugees (BAMF) in the asylum and Dublin procedure departments. Mr. Atas has been admitted to the bar since 2018 and worked in a mid-sized law firm in the Mönchengladbach area, specializing in migration, social, and labor law. Since June 2024, Mr. Atas has been part of our team at Maibaum Rechtsanwalts GmbH. He is a member of the Migration and Social Law Working Groups of the German Bar Association, a member of the Cologne Bar Association, a member of the Young Lawyers Forum, and a board member of the Mönchengladbach Bar Association. Since 2023, he has volunteered as a supervisor for the Refugee Law Clinic (RLC) in Düsseldorf. Mr. Atas advises our clients in both English and Turkish.

Our Team of Experts 6
Lilian Tabatabai

Ms. Lilian Tabatabai is a prospective legal assistant who began her training with us at Maibaum Rechtsanwalts GmbH in September 2024. Ms. Tabatabai works reliably and meticulously, already showing strong organizational skills. She is fluent in Persian and proficient in English, making her a valuable asset to our firm and to our clients.

Our Team of Experts 7
Stephanie Mauer-Otto

Stephanie Mauer-Otto studied law at the University of Cologne. At first, she worked for the law firm Emili+Maibaum and then, after completing her paralegal training in 2015, went on to work for Maibaum Law Firm. As Office Manager, Mrs. Mauer-Otto has been the first point of contact for all our clients' concerns for many years.

Birte Windheuser
Sandra Spillmann

Sandra Spillmann successfully completed her training as a paralegal in 1997. From 1999 to mid-2022, she worked in a law firm specialising in immigration law. Since September, Ms. Spillmann has been a great asset to our clients with over 20 years of professional experience in the field.

Our Team of Experts 8
Pia Adler

Pia Adler hat 2017 ihre Ausbildung zur Rechtsanwaltsfachangestellten erfolgreich abgeschlossen. Von 2018-2022 war sie in der Kanzlei Gunter Christ im Ausländerrecht tätig. Seit dem 1. Januar 2023 ist Frau Adler durch ihre einschlägige Berufserfahrung auf dem Gebiet des Ausländerrechts eine große Bereicherung für unsere Mandanten.

Gunter Christ
Tom Zierhut

Tom Zierhut is a law student at the University of Cologne and successfully passed the first part of the state examination (erstes juristisches Staatsexamen) in 2021. He has been working as a research assistant at Maibaum since February 2023.

During an internship at a German-Portuguese law firm in Lisbon, Portugal, Mr. Zierhut started familiarising himself with foreign legal systems. At a later date, he completed an internship at the German Embassy in Addis Ababa, Ethiopia, where he gained valuable insights into the legal department and the visa process. Mr. Zierhut also spent a term studying abroad in Gujarat, India. Here he was able to further develop his intercultural skills and, in particular, acquire additional knowledge of English legal terminology. During his studies, Mr. Zierhut gained practical experience as a student assistant and research assistant in various law firms in Cologne and Düsseldorf. He also volunteers for the Refugee Law Clinic Cologne. Mr. Zierhut's wide-ranging experience and in-depth knowledge of the law make him a great asset to our clients.

Our Team of Experts 9
Blerta Jonuzaj

Blerta Jonuzaj successfully completed her training as a paralegal in 2020 and already gained experience in an immigration law firm during her training. Ms. Jonuzaj has been part of our team since 2021 and works in the secretary with great dedication for our clients. Ms. Jonuzaj is fluent in Albanian, Greek, German and English.

crossmenu